Sensitivity Training: Determining the Correct Climate Sensitivity

Guest post by John Kehr from: The Inconvenient skeptic

There are many times when I am putting together articles that I need to compare the results of my research to the models of the theory of Anthropogenic Global Warming (AGW).  In this manner I can contrast the results and predictions directly. This way I understand how the different views relate to each other.

Recently I was trying to find the total amount of energy (forcing) that the warmists claim CO2 is responsible for in the atmosphere. The reason I wanted this is because I have recently completed my full analysis of absorption and I wanted to compare my results to the warmist views. While this article is not about my results, it will focus on some interesting results that I found using their models.  Because I was searching for the warmist views about energy I was using information from their sites (and citations of course).  While that might seem strange, they generally have lots of good information there.

The starting point is the basic equation they use to determine the forcing caused by a change in CO2 concentration.

The Inconvenient SkepticCO2 Forcing Equation

This equation provides the amount of energy in W/m2 that a difference in two CO2 concentrations should cause.

While looking for the total forcing of CO2 in the atmosphere, I found an interesting article on the Skeptical Science (SkS) site that had an answer to my question (citation).  They state that the radiative flux caused by CO2 is 32 W/m2.   I will use the information from that article several times.  When I compare the energy calculated by the forcing equation using CO2 levels of 1 ppm and 390 ppm I get a result of 31.9 W/m2.  So far things are looking consistent for the theory of AGW.  Here is a chart of the forcing from 1 ppm to over 1000 ppm.

The Inconvenient SkepticProposed Model of CO2 Forcing

The next step is to determine how much warming this energy causes.  For this I use the next important equation that the AGW model uses.  That is the climate sensitivity.

The Inconvenient SkepticClimate Sensitivity: Warming caused by Forcing

Again I found lots of discussion and references at the SkS website (Hansen et al. 2006) where they provide their views about climate sensitivity.  This equation is straightforward and simple to decipher.  They generally calculate it by looking at a period of time with a temperature change and then estimate the change in forcing.  For example if increasing CO2 caused a forcing of 2 W/m2 and the observed temperature change was 5 °C, then the climate sensitivity would simply be 2.5 °C /(W/m2).

One thing to be aware of is that the sensitivity is usually not shown directly. Most warmist publications display the results in terms of temperature change that will happen as a result of forcing. For example the most commonly used quantity for climate sensitivity is 3.0 °C for a doubling of CO2. To determine the climate sensitivity they are using it is simply:

 

λ = (3°C / 3.7 W/m2 ) = 0.81 °C/(W/m2)

 

I am going to use the direct climate sensitivity instead of the temperature effect that a forcing will cause. This will make my numbers look a little different, but here is the conversion.

The Inconcenient SkepticProposed Range of Climate Sensitivity

 

When comparing climate sensitivity it is very important to know exactly which form is being used. I will be using the actual climate sensitivity instead of the CO2 doubling form. The best way to check is to look at the units being used.

The most common estimate is the 0.81 °C/(W/m2). That is what corresponds to the 3 °C temperature increase for a doubling of CO2. The full range is what I have shown in the table. Some estimates do go a little higher or lower, but the 0.43-1.13 °C/(W/m2) is the most widely accepted range.

SkS puts the climate sensitivity at the 0.81-0.92 °C/(W/m2). I am going to use the 0.81 °C/(W/m2) as the default value for the warmists as it is the most commonly used value.

So far all of this seems perfectly reasonable and hopefully acceptable. This is also where the wheels start to come off.

I decided to look at another method to determine the climate sensitivity. I am troubled by the method normally used because it is very hard to know the exact forcing and cause of the temperature change. So I decided to use what should be a less controversial method, but somehow I doubt it works out that way.

I decided to use the total Greenhouse Effect (as the ΔT) and then the energies involved. The total Greenhouse Effect is perhaps the least controversial aspect of the Global Warming debate. I will use the normally accepted value of the Greenhouse Effect as 30 °C.

Now by using the climate sensitivity value it is possible to compare what portions of the Greenhouse Effect (GHE) are caused by different components. Since the accepted forcing value for CO2 is accepted as 32 W/m2 it is now possible to determine the total impact that CO2 has on the total GHE.

 

ΔT = (0.81°C/(W/m2)) * 32 (W/m2) = 25.9 °C

 

While that might not immediately seem unreasonable. The entire stated effect of the GHE is 30 °C. So according to the accepted climate sensitivity and CO2 forcing equations, CO2 accounts for 86% of the total GHE.

So all other factors in the Earth’s climate account for 14% of the GHE and CO2 by itself accounts for the other 86%. This can also be compared to the number of CO2 doublings that take place from 1 ppm to 390 ppm. That is roughly 8.6 CO2 doublings (1,2,4,8,16,32,64,128,256,390 ppm). Using 8.6 doublings from 1 ppm gives 25.8 °C. So their model is coherent, but saying that CO2 causes 86% of the GHE is extremely incorrect.

This means that the methods being used for determining temperature change based on forcing and climate sensitivity are flawed. Any result that puts CO2 at 86% of the GHE is wrong. Earlier I showed that the forcing model and the accepted total forcing have a good match. That would indicate that the problem is with (at least partially) the estimated climate sensitivity.

So I worked backwards. Assuming that the total temperature change caused by the GHE is 30 °C and then the total energy inputs are the total forcing. The total GHE is not very controversial. Very few people will argue that the Earth is not warmer as a result of the atmosphere. Without the atmosphere the Earth would be around -15 °C and with the atmosphere it is currently about 15 °C. That 30 °C difference is caused by the insulative effect caused by the atmosphere.

That leaves forcing as the problem in determining the correct climate sensitivity. The same article that stated CO2 as 32 W/m2 also stated that water vapor causes a forcing of 75 W/m2. If I assume that water vapor and CO2 are the ONLY factors I get a total forcing of 107 W/m2. This would indicate:

λ(30%) = (30°C /107W/m2) = 0.28 °C/(W/m2)

 

Already using very poor assumptions the climate sensitivity is already much lower (by almost 3x) than the accepted value. This still puts CO2 at 30% of the total GHE, so even this estimate for climate sensitivity is still too high.

The normally discussed range of CO2 effect on the GHE is 9-26%. Assuming that the 32 W/m2 remains accurate for the forcing magnitude of CO2 results in climate sensitivities of:

λ (9%) = (30°C / 356 W/m2 ) = 0.08 °C / (W/m2 )

λ (26%) = (30°C / 123 W/m2 ) = 0.24 °C / (W/m2 )

 

At 9% of the GHE the climate sensitivity must be 10x lower than what is currently accepted. There is one more possible scenario that I want to cover.

If I look at the Radiation Budget (Kiehl, Trenberth 1997) I get a total forcing from the surface to the atmosphere of 452 W/m2. That would include the energy from evaporation, convection and radiative transfer and subtracting out the open window of 40 W/m2. If I use the 32 W/m2 for CO2 with that total energy then CO2 accounts for 7% of the total GHE. Then the climate sensitivity is:

λ (total energy) = (30°C / 452 W/m2 ) = 0.066 °C / (W/m2 )

 

That is what the real lower limit of the climate sensitivity is. The flaw in the estimates for climate sensitivity is the assumption that all temperature change is caused by the greenhouse gas forcing. If the climate was as sensitive as the much higher estimates currently in use are, the Earth would be a very unstable place as small changes in energy would cause large changes in temperature.

Using the total GHE determined climate sensitivities, here are the CO2 doubling effects on the climate.

The Inconveneint SkepticGHE Determined Climate Sensitivities

What this shows is that trying to determine the climate sensitivity from a change in measured temperature and then assuming it was caused by a particular forcing is incompatible from the determination of climate sensitivity from the actual GHE.  In choosing between methods it is the GHE that is a known quantity.  Since the measurements have been done to determine the individual parts of the GHE, that seems to be a much more reliable method than “assuming” that a particular forcing caused a certain change in temperature.

The IPCC and the general AGW method of determining climate sensitivity is about an order of magnitude different than the method of using the total GHE and then calculating the components.  This is a significant scientific disparity.

The difference the climate sensitivity makes to the temperature projections based on increasing CO2 concentrations are significant.  Assuming the same CO2 forcing while using the different climate sensitivity values results in the following effects of CO2 on the global temperatures.

The Inconvenient SkepticRed: The AGW accepted climate sensitivity of 0.81 (3C for doubling) Green: Climate sensitivity of 0.28 (1C for doubling) Blue: Climate sensitivity of 0.066 (0.24C for doubling)

The total GHE of 30 °C is incompatible with the currently accepted IPCC values of climate sensitivity and CO2 forcing.  In order for the GHE to be compatible, the total effect of the greenhouse would have to be closer to 100 °C which would result in a global temperature of ~85 °C.  This strong overstatement of the climate sensitivity substantially weakens the idea that CO2 could cause measurable change in the Earth’s climate, much less the type of danger that is often being stated.

This does not mean that CO2 is not a significant portion of the Earth’s greenhouse, but it does limit the role that it plays in the total GHE.  The climate sensitivity is what prevents the sum of the parts from being greater than the whole and the sum of the parts cannot be greater than the total observed GHE.  If the current estimates of CO2 forcing and climate sensitivity do not fit within the parameters of the total GHE effect, those estimates must be incorrect.

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185 thoughts on “Sensitivity Training: Determining the Correct Climate Sensitivity

  1. John, John, JOHN!
    Don’t you know you are just an “engineer”, and you just don’t have the finese, the “intellectual horse power” to handle these things? In point of fact, engineers should NEVER go out of their domain…(Think of that disasterous Frank Capra, Hollywood producer: Chemical Engineer, or Neville Shute Norway, Novelist: Metallurgist..whoops, I guess that’s a bad set of examples, they were succesful in both fields.)
    Or imagine an untrained person, but bright and “on the job learning” type
    doing good science (Micheal Faraday?)
    Or a composer doing Chemistry? (Camielle Saint Seans?)
    Shame on you for having the chutzpa to THINK that you could “compete” with the likes of Hanson or Pachurri! (Wait, wasn’t Hansen originally in phyics, and Pachurri a RAILROAD engineer?)
    Well, you’ll figure out the errors of your ways eventually. No pressure, really!

  2. There was a similar post to this on WUNT a month or two back. Not surprisingly they share the same flaw.
    The greenhouse effect of 30C is for a planet with an albedo of 0.3. The earth would not be cooler by more than 30C if the atmosphere was not radiatively active because the albedo would increase because of increased snow and ice cover. You can see this effect in Lacis et al. 2010 http://www.sciencemag.org/cgi/content/short/330/6002/356

  3. This is amazing work, assuming that their science is coherent, this makes sense to me in “the real world” in that CO2 might have a small effect (including forcing value), but its not the thermastat so to speak. This would also seem to correspond to other views on how CO2 does most of its work in the first couple of doublings so to speak.
    I applaud the science, this might help us when we try to understand the climate better.

  4. A minor editorial note: Thanks for including the boxes with conversions between two ways of expressing sensitivity.
    It would be helpful to add a third line with the other common method of describing sensistity — watts/meter-squared/degree K.
    That line would just be the reciprocal of your °C / (W/m2 )

  5. This makes sense. The rate of warming looks to be out by an order of magnitude. If the climate was highly sensitive to CO2 forcing, the observed temperature now would be much higher. Hansen’s original model put the anomoly over 1C by 2010. Put simply this model has failed. It has failed because of this fatal climate sensitivity flaw.

  6. “If the current estimates of CO2 forcing and climate sensitivity do not fit within the parameters of the total GHE effect, those estimates must be incorrect. ”
    Or, there is a strong negative cloud feedback not included in the models to date?
    Caution, I’m a climate dummy. Please forgive if the question is dumb.

  7. The whole concept of a climate senstivity which is independent of temperature seems a little strange to me.
    Stable systems tend to become less sensitve to an input as they get pulled from the mean. The faster a car goes the more energy it takes to get a little bit faster. Models which suggest that an input which increases into the future will continue indefinitely and would never cause an increase in the negative feedback don’t seem particularly plausible to me. The more energy a system has, the faster it tends to leak away, and relying on a computer model – even if it accurately predicted the current situation – does not demonstrate its ability to predict an environment that has never been experienced.

  8. So much of the CAGW dispute is conducted within ideological camps that both errors and bias in approach are extremely difficult to determine regardless of one’s position. Is there a “reasonable” pro-AGW site that could become part of a dialogue instead of the other side of two monologues, and review these reviews?
    There will never be a sense of peace or harmony in the climate change dispute if serious dialogue does not develop in the blogosphere. The academic disputes are insulated within their towers and, well, academic. Both sides receive professional and personal support for their positions even if later these positions change. The place where distrust and acrimony will live is in the literate but non-professional arenas such as WUWT. We need to find some foe, if not friend, to sit at the table and engage in discussion.
    Is there anyone out there or are we more victims of the two solitudes?

  9. Then there’s that pesky Vostok data hanging out there that shows atmospheric concentration of CO2 follows warming. How does the observed relationship between warmth and atmospheric concentration of CO2 square with the mathematical models? Should there not be a rigorous experiment to test the mathematical models?

  10. Since there is substantial overlap in the absorption spectra of CO2 and H2O, you cannot simply add their contributions. The net absorption will be substantially less than the absorption of the individual components.
    This is just one of many mathematical non-linearities in the climate system that are traps for the unwary (see Willis’ immediately preceding post for others). Most introductory classes in various types of systems analysis work pretty exclusively with linear systems, because they are easier to handle — it is very easy to forget this very strong assumption.

  11. Thank you… VERY interesting and informative…
    I wish I could say I was surprised or shocked… but I can’t… I’m simply lost for words… May the Intergovernmental Panel of Climate Charlatans rest in peace… while we try to remain respectful by not dancing on their computer simulated graves.

  12. Abit off topic but i just saw a news thread on FOX news that said that NOAA had just opened a new center with a new super computer that they claim will be able to make better weather and CLIMATE predictions than ever before. They claim it will be able to make yearly and decadel predictions like never before, Like the METUK computer that seems to make wrong predictions it will probrably make just as bad of a job of it.

  13. The real issue will be if our “sensitivity” will endure the chilling cold ahead. It has been demonstrated here in WUWT, “ad nauseaum”, all that issue of Global Warming/Cimate Change/Climate Disruption, was a scam aimed at making business from pouring the empty into the void: buying “carbon credits” to third world countries at a peanuts’ price and selling “carbon shares” to “polluters” at a thousand times prize. The businesmen in between thus would happily profit. But, it happened in November 2009 what was called the “Climate Gate” and the rest is history…..
    All characters in this, at the beginning, horror movie on a terrible armageddon to happen to earth and the humand kind, have turned into characters of a Travesty Comedy, really painful to bear .
    It’s over buddy!

  14. Quote: “While that might not immediately seem unreasonable. The entire stated effect of the GHE is 30 °C. So according to the accepted climate sensitivity and CO2 forcing equations, CO2 accounts for 86% of the total GHE.”
    This shows exactly what is wrong with the GCM’s and AGW-theory, because as far as I know H2O accounts for 85%-95% of the greenhouse effect.

  15. Now, why not rework all those numbers but treat the oceans as part of the atmosphere for solar energy retention purposes ?

  16. Thanks Mr. Kehr for a very logical and well-written article. This is a new and powerful argument in my arsenal against the AGW fraud.

  17. “extremely incorrect…..”
    now take me for a simple geologist but you can be either wholly correct or wholly incorrect, there are no degrees of correctness (unless you’re a geophysicist)
    “An engineer is asked, what is 2 +2 , Engineer replies 4
    A climatologist is asked what is 2+2, climatologist replies, 5
    A geophysicist is asked, what is 2+2, geophysicist replies, what would you like it to be?!
    boom boom crash.

  18. Curt says:
    October 25, 2010 at 8:28 am

    I had to read this twice, and I do not think this is translating into “this linear model is correct”. I call it a model simply to make it easier to look at.
    The normally discussed range of CO2 effect on the GHE is 9-26%. Assuming that the 32 W/m2 remains accurate for the forcing magnitude of CO2 results in climate sensitivities of:
    Normally I would agree with you, but this is just a simple start to figuring out the actual sensitivity. 9-26% does not translate into a linear relationship to me per se. The 9-26% agreed upon I would believe translates into the overlap so to speak, which is why we have disagreement on the actual contribution of CO2. More then likely, even though its not going to be linear, the contribution of CO2 can be measured to “estimated guesses” by statistical methods. This is where you start good science in my mind to fine-tune it even better. I doubt it will come out linearly at all in the end, but it might be possible to estimate with a straight line so to speak.
    There is a wide range of error obviously, but this is where I would think you would start to estimate the actual climate sensitivity. Right now, the methods uses are terrible by climate scientists and have not matched reality at all. This particular method could be tested unlike those models which are just meant to scare.

  19. Look John, there’s no place for common sense or full-circle thinking in climate science o.k? Keep re-working your equations until you get the desired outcome (Sarc-off).

  20. When they discuss the warming from a doubling of CO2 with a sensitivity of 3 degrees for that doubling, they include the amount of warming from the water vapor feedback in that calculation.
    It doesn’t make any sense to then remove that feedback when discussing the contributions of water vapor and CO2 to the greenhouse effect.
    After all, something has to provide the warmth to keep the water vapor in its gaseous state, and that something is CO2.
    The warmer it is the less cloudy it is, or hasn’t anybody noticed that.

  21. Very good demonstration. I find it incredible that scientists fixate on CO2 and ignore thermodynamics (adiabatic equilibria), evaporation/transpiration, meridional atmospheric circulation, clouds, solar interactions, etc., except that they have the idea that water vapor feedbacks will propitiate the very minor CO2 effect. Convection removes heat from the surface, otherwise we would be living in a Super Sahara world, even more terrible than the one envisioned by the warmers. We wouldn’t even be here.

  22. Two items:
    1. If you use the dF = 5.35 ln(C/Co) formula and take that input for Q = Cp*m*T over a one year time you will find as I did that there is “missing heat”.
    2. I have pointed out several times on various blogs that the atmosphere exerts a large pressure on the earth. PV = nRT must be factored into the discussion. Under standard conditions (STP) this is 273 K or 0 C. So the maximum you need to account for in “GHE” is 15 C. Steve Goddard’s “Venus” post is an excellent example of why pressure matters.
    Watts per meter squared mean nothing unless there is a frequency attached to it. My mircowave has more then 1000 W/m^2 but does not heat the air inside it, only the food. The base of a 50000 W transmitting tower should be the hottest place on earth, but it’s not.
    CO2 is said to absorb at 2.3, 4.7 and 15 mirco. The 15 micro converts via Wien’s Law to about 200 K. If the surface is at 300 K CO2 will be uneffected.
    The IPCC is wrong but for lots of reasons.

  23. Another nail, and a rather large one at that, through the heart of the walking corpse of AGW.
    I enjoyed Max H. humorous comment above.
    How do we get the politicians or their aides to read so many posts that forensically destroy the theories and assumptions of the climate mainstream?

  24. I have a problem with the formula for climate sensitivity. How can one simply divide the change in temperature by the change in forcing without including the element of time? When you put a pot of cold water on the stove, it doesn’t get warm immediately – you have to wait until it reaches equilibrium. Am I to understand that the warmers believe that adding CO2 to the atmosphere produces an instant increase in temperature? If not, what time constant do they assume?

  25. Well John, Let’s take a look at your final graph(s); specifically the ones with 3 deg C per doubling, and the one for 1 deg C per doubling. Those hapen to be within the IPCC 3:1 fudge factor range.
    Well their numbers would be 4.5 deg C per doubling and 1.5 deg C per doubling; but it makes no difference.
    You have plotted your curves for (near) zero to 800 ppm. But we have actual real experimental credible values that go from 315 ppm to 390 ppm for the Mauna Loa Record.
    That is a ratio of 1.238. The cube of that is 1.899; slightly less than 2.0 while the 4th power is 2.350, so one would guess that 1.238 is close to 30% of one doubling. (i’m too lazy to do the real log calculation).
    So for all of the credible non proxy global record of CO2 concentration since 1957/8, the IGY year we have data suggesting 30% of one doubling has occurred.
    So if I take your graph and imagine your numbers were for 4.5 and 1.5 deg rather than 3 and 1, and now I scatter a bunch of observed data points; at least 52 of them for the elapsed years, in between 315 and 390 ppm and maybe centered about the middle between your two graphs but extending out to them as plausible upper and lower probably values; so I have that space shot full of at least 52 holes in a “Scatter Plot”; and the characteristics of that scatter plot of real observed data are such that your upper curve (3 deg>ersatz 4.5) and your lower curve (1 deg > ersatz 1.5) are pausible fits to that scattered data.
    So there is the real data posted on top of your (and the whole house of climatists) theory of “Climate Sensitivity”.
    So my question is simple:- Where do you collectively get the gall to claim that despite such a scattered data picture (of 52 spots) you know that the best fit line to that data, is in fact a logarithmic curve.
    Try drawing a STRAIGHT LINE between the 315 and 390 ppm points on your two graphs; and now try to sell me that the scattered data better fits the log curves than it does the straight line linear curves.
    I put it to you that your graphical curves, and the known Mauna Loa data provide NO EVIDENCE whatsoever, that in fact Temperature is related to log of CO2 abundance.
    As a follow up experiment; you could take the often reported Temperature and CO2 proxy data for 600 million years dating back to the preCambrian; and encompassing Temperatures from +12 deg C to + 22 deg C, and CO2 values ranging from aorund 7000 ppm down to around 200 or so, meaning about 5 inverse doublings; and now repeat the above data plot but now over five doublings instead of 0.3 of one doubling. Try to justify your log model with that set of data.
    Well i’m sure that won’t work either; neither one of those data sets will convince anyone that the relationship is in fact logarithmic.
    So let’s try the theoretical approach. Styarting from basic laws of Physics; maybe we can prove that the relationship is logarithmic.
    Well we know that the physics of CO2 greenhouse effect starts with LWIR thermal black body like radiation from the surface of the earth (oceans and land), directed up into the atmosphere; and Trenberth gives that a value of 390 W/m^2 corresponding to a mean global Temperature of 288 Kelvins. (+15 deg C). That radiation is selectively absorbed by CO2 which we are told is well mixed in the atmosphere so it is the same all over the earth, so it should absorb the same amount of radiation all over the earth.
    Well hang on a minute; there’s a bit of a problem. You see the whole of the earth surface is NOT at 288 K TEmperature. In the Antarctic highlands around Vostok station; there are places that can get down to just 183 K or -90 C, and Vostok itself has recorded within one deg C of that. That is just 63.54 % of the global mean of 288 K, and for such a Temperature, the surface radiation limit would be just 16.3% of 390 or 63.6 W/m^2 (max). It might be less than that based on spectral emissivity.
    So we have a problem that some of the earth surface emits only 1/6th of that emitted at the global mean temperature so in those regions, the climate sensitivity due to CO2 must be very much less than 1.5 to 4.5 deg C per doubling; since you have only 1/6th of the driving energy.
    At the other end, you have arid desert tropical regions, where actual surface Temepratures easily reach +60 deg C; and official weather station records have come within a few F degrees of that (for the air temperature). And on some paving surfaces Temperatures of +90 deg C have been measured (the egg cooking experiments); but we’ll just take the +60 which gives us 333 Kelvins; which is 15.6% above the global mean of 288 K. So the max BB surface emission could be 1.787 times the 390 W/m^2 Trenberth gives; or 697 W/m^2. Well that is eleven times the min value for the Vostok region; and because of the seasons; both of those extremes could occur simultaneously.
    So from a physical theory point of view we cannot compute the CO2 energy interception amount, without knowing the Temperature of the surface which is emitting the driving energy.
    But apart from the fact that we don’t even have a starting constant energy source driver; nothin in that Temperature range information yes insists that the surface Temperature (which controls the driving source) is then logarithmically related to The very temperature which is the start of the whole sequence.
    So clearly “Climate Sensitivity” has a different value over a very wide range, depending on where you are on earth. Are you aware of any global network that constantly monitors the local value of climate sensitivity ; to compute a globalk average value ? I’m not !
    It would seem that we don’t have any sampled data with which to establish a physical theory of climate sensitivity; that derives a mathematically logarithmic relationship between average global surface temepratures, and average global (well mixed) atmospheric CO2 abundance. The likelihood that a complex array of interractions between parameters some of which range over more than an order of magnitude should somehow come up with a theoretical logartihmic relationship for averaged data, is rather remote.
    So far, I’ve seen neither credible experimentqally observed data, nor basic physics derived theoretical relationship, that supports a logarithmic connection as a better fit than say a linear fit; or any other mathematical relationship. The experimental data doesn’t fit ANY well behaved continuous function; sometimes the two variables increase together or decrease together and sometimes they go in opposite directions. There are well known time delays between some of the physical phenomena. For example there is a delay between ocean warming, and release to the atmospehre of extra CO2 since there is more CO2 at colder deeper levels, which has to propagate to the surface to enter the atmosphere; so that would require that there be some offset time between the CO2 and Temperature data sets, to arrive at properly related values; but no possible delay of either data set, can be shown to produce a logarithmic well behaved connection as more plausible than say a linear fit.
    It seems that someone; apparently the late Dr Stephen Schneider I’m told, simply invented the logarithmic relationship out of whole cloth; and climatists don’t seem to find that a problem. Well whoever dreamed up cs; and my sincere apologies to the late Dr Schneider if in fact it wasn’t him; there’s no data or theory that supports such a relationship.
    So trying to do ever more arcane statistical analysis on chaotic random data, to derive on some new grounds a “better” value for Climate Sensitivity, just seems to be a total waste of the taxpayer’s money in the form of government research grants or agency funding.
    Other than that John Did your inclusion of the water vapor “forcing” include the simple and incontrovertible fact that water vapor (any water vapor) ALWAYS reduces the ground level solar insolation; so in that sense it would cause a negative forcing; not a positive one.
    I don’t know John whether you have ever experienced a total eclipse of the sun; I never have but I have friends who chase them; like the Druids gathering at Stonehenge; but I have observd many partial eclipses; and in a partial solar eclipse; we get an instant demonstration of what would happen if the value of the TSI should drop. The instant effect for even a 30% partial eclipse is that the daytime temperature immediately plunges given an open cloudless sky.
    So what if the TSI permanently dropped by 30%. It would get colder; but presumably you would get a lot of precipitation of rain/snow/sleet/hail/wtatever, and eventually some of that cloud would disappear; so more of the reduced sunlight could eventually rach the ground. So over some short time frame, the cloud level would adjust to the new lower TSI and we would have a lower total global cloud cover; but the net ground level solar insolation would be lower than before but not 30% lower; the cloud change would recover some of that.
    But it is inescapable; that if you lower the value of TSI; then the earth must get colder; and conversely if you raise TSI, the earth would get warmer; but cloud adjustments would partially compensate for the TSI change (how much I don’t know).
    Well just as a partial solar eclipse lowers earth temperatures; and a lower TSI would do so too, so too would any long term increse in global cloud cover reduce temepratures since clouds ALWAYS reduce ground level solar insolation as does water vapor.
    So regardless of what H2O does with LWIR (or irregardless, as the case may be); MORE H2O in the atmopshere in ANY and ALL phases ALWAYS reduces the total solar energy that is absorbed by this planet; just as a lower TSI would; and over time that must lead to a cooler planet.
    So just where climatists get off claiming H2O and Clouds as a positive feedback warming mechanism; is beyond me.
    Now that doesn’t mean that H2O does not warm the earth or the atmosphere. We know from the arid high desert night temperature drop, that CO2 is not capable of holding up surface temepratures; but in the presence of H2O the cooling rate is much lower at night.
    But it is the three phase presence of H2O that provides the regulation via the mechanism of cloud modulation. And as Gavin Schmidt has recently made very public; H2O it the ONLY condensible GHG in earth’s atmospehre; so it is the ONLY one that is capable of providing offsetting warming and cooling effects; and it can do all of that without any assisitance from CO2; either logarithmically or linearly.

  26. Needs work. (1) The calculations are not shown. and (2) the chain of thought goes fairly straight until suddenly, you whip out this statement without (as near as I can tell) reference or provenance or support:
    “The normally discussed range of CO2 effect on the GHE is 9-26%.”
    Where did this come from? If this statement is wrong, the entire argument from then on has no merit. Please fill in the missing train of thought. All of it.

  27. George E. Smith says: “…Try drawing a STRAIGHT LINE between the 315 and 390 ppm points on your two graphs; and now try to sell me that the scattered data better fits the log curves than it does the straight line linear curves…”
    A straight line will approximate the curve for small increments of CO² concentration. This does not disprove the logarithmic nature of the overall correlation.

  28. Doug Proctor says

    The place where distrust and acrimony will live is in the literate but non-professional arenas such as WUWT.

    Being “professional” doesn’t necessarily translate into being “correct”. An ivory tower is unscalable only where dissent is eliminated, as in Real Climate. So WUWT is not an “ivory tower” per se, but also is NOT a non-professional arena.
    So contrary to your statement, distrust of places like Real Climate will live on; acrimony is not found there because dissent is not allowed there. Dissent at WUWT is encouraged, which fosters trust whereas acrimony is generally self-policing and fades away.

  29. I wonder if you are lumping conduction into convection in this statement?
    I will also offer this observation: If CO2 contributed 86% of the GHE (I prefer Atmospheric Effect) consider what would happen on a very clear night in contrast to a high humidity night. Say the temperature dropped 5 C. degrees with a high humidity night. With the same starting temperature but a clean and very low humidity atmosphere the temperature might drop 20 C. degrees. But the CO2 is still there with its purported 86% contribution. Thus, we’ve just gotten a 15 C. degree drop from removing just 14% of the contributing GHGs. If we could then remove all of the CO2 should not the temperature respond by a corresponding drop of about ~ 92 C? [ (86/14)*15 ] That seems unlikely.

  30. OOPS! This statement:
    . . . a total forcing from the surface to the atmosphere of 452 W/m2. That would include the energy from evaporation, convection and radiative transfer and . . .

  31. Richard:
    Please inform us as to how there would be snow cover without an atmsophere. That assumption wouled require that there was at least an atmosphere of only water vapor and that was precipitated out as snow leaving a dry vacuum. Pretty silly yes? If the iceans were never able to evaporate the ice would be a very dark color not white and would absorb heat probably better than land surface. Again this is impossible as the exposed water would indeed evaporate and create an all water vapor atmosphere how thick? I have no idea. But snow does require this and it would also require there would be a green house effect. Get rid of the water and you have the no atmosphere model.
    Barry S.

  32. I believe that GHE should be viewed as a resistance to the rate of energy lost to space, not a “force”. In the radiative equation W=kT^4, T^4 is the force and 1/k is resistance. GHE increases the resistance 1/k and reduces k. Using this approach in a statistical analysis of the Reanalysis data, I find that evaporation/condensation and freeze/thaw rates are the rate controlling processes. A possible CO2 effect of reducing k is not observed with statistical significance. http://www.kidswincom.net/CO2OLR.pdf.

  33. bob says: at 8:59 am
    After all, something has to provide the warmth to keep the water vapor in its gaseous state, and that something is CO2.
    Sometimes it is cold and clear, sometimes cold and cloudy, sometimes warm and clear, and sometimes warm and cloudy. Sometimes there is CO2 in the atmosphere, and sometimes there . . . Oh, wait a minute!

  34. steven says:
    October 25, 2010 at 8:31 am
    I believe the models would consider water vapor a feedback instead of a forcing.

    As water vapor can evaporate all on its own without the presence of CO2 or warming and humid air is lighter than dry air, water vapor will cause convection and winds all on its own. If the convection or winds over landscape result in clouds then they raise albedo again independent of CO2. Given the effect of the Coriolis force, the sun’s insolation and the winds that result in the Hadley and Ferrel cells and the dropping cold dry air into the polar regions. All without CO2 …..
    It seems that the choice of wording whether to call water vapor and clouds in the atmosphere forcing or feedback is dependent on what is wanted to be proven. So if you believe that everything would sit in stasis without the presence of CO2 – then you call every change from stasis a feedback. Regardless of how wrong that is.

  35. Sorry, I left the i out of the . Should be . Two mistakes in just a few minutes. I’ll go outside now and get some fresh air.

  36. Your argument will be more difficult to argue against since you included the “total forcing from the surface to the atmosphere of 452 W/m2”. Thanks for that. — John M Reynolds

  37. Do the radiation calculation and the real Greenhouse warming should be c. 60K. The fact that it’s c. 33K is because a lot of the heat is convected upwards by weather so lower atmosphere temperatures are reduced substantially. So that is one reason why the models used in Skeptikalscience article are wrong and you can’t trust that 32W/m^2!**
    **It’s because the equation derived by Hansen and Lacis in 1974 to calculate cloud albedo from optical density, used off-set high predicted CO2-AGW by the cloud part of global dimming, is plain wrong, even though it came originally from Carl Sagan. It only considers internal diffuse optical scattering and there’s a second process which can dominate in thick clouds. Thus, the ‘cloud albedo effect’ cooling [0.7 W/m^2] is imaginary and if you put in the correct physics, you should get heating, possibly another form of AGW.
    Thus there is very little you can trust except experiment, and that shows global warming apparently ceased in 2003!

  38. You reference the Keihl, Trenberth document. FIG. 7. The earth’s annual global mean energy budget based on the present study. Units are W m-2. From that figure I would like to suggest that the 107 Wm-2 that is reflected is also out of play for the GHE and therefore 195 Wm-2 (342-107-40) would be the correct approximation for the amount of radiation subject to the GHE and yielding a sensitivity of ~.15 Deg C/W m-2.

  39. Thanks for all interesting feedback.
    As I stated at the beginning of the article I like to compare results and models. There are many valid points about the total GHE being larger than I used.
    The main take away I get from this is that the more energy is involved in the total system, the less impact a change will have. There are many estimates that put the actual climate sensitivity in the range of 0.24-0.30 °C/(W/m2), myself included.
    There is so much energy involved in the current steady state system that the small proposed “forcing” by CO2 is trivial. I used the 32 W/m2 for CO2 even though I strongly disagree with that value. That is why I had to search for the warmist value because they clearly need a large value to support their theory.
    Thanks for the support.
    John Kehr
    The Inconvenient Skeptic

  40. As DR notes above Roy Spencer and Lindzen’s published papers supports the assertion the feedback is negative rather than positive. (Planetary cloud cover increases or decreases to regulate planetary temperature.)
    Spencer explained why previous analysis appear to support the assertion that the feedback was positive rather than negative, at a presentation made at the 2009 AGU fall meeting and in his published paper. (The problem in the past analysis was timing of the effect. Tail wagging the dog vs dog wagging tail.)
    http://www.drroyspencer.com/2010/09/why-33-deg-c-for-the-earths-greenhouse-effect-is-misleading/

  41. John Kehr, fine article.
    Your simple approach IS proper science and don’t let anyone tell you otherwise. Those pieces have been rattling around in many minds and comments here but you had a fantastic way to put it all together and explain it, I’ll study your style!
    When I said a couple or weeks ago that co2 had NO affect on Earth’s temperature I have kicked myself for stating it so absolutely, very un-scientifically-like. That shallow curve in graph two most very likely explains Mislolczi’s IR optical thickness all of the radiosondes have recorded, the differential is then shallow enough to not register and plot as a single point within tolerences. Once again, great, great article!

  42. I have read your post twice & do not see any obvious flaws in logic. I would love see a warmist post on here an analysis of why this is not a correct analysis. If the warmist camp can’t refute this logic, then the analysis posted here is as strong as any why the alarmist position is invalid.
    On a related note, it also explains why temp data has been shown again & again to track such things as ENSO, NAO, PDO, etc – if CO2 forcing is small, it will be hard to see in the observed signal.
    I would also love to see Dr. Spenser’s take on this analysis. Do you think this is a solid /defendable analysis of sensativity & forcing?

  43. richard telford says:
    October 25, 2010 at 7:51 am
    There was a similar post to this on WUWT a month or two back. Not surprisingly they share the same flaw.
    The greenhouse effect of 30C is for a planet with an albedo of 0.3. The earth would not be cooler by more than 30C if the atmosphere was not radiatively active because the albedo would increase because of increased snow and ice cover.
    #
    What does a state change discontinuity at boundary have to do with the anything?

  44. @Kehr in OP
    “That 30 °C difference is caused by the insulative effect caused by the atmosphere.”
    Variable albedo plays a potentially huge role. The earth and the moon would have substantially the same albedo absent ocean and atmosphere. The moon’s average temperature (as measured deep enough into the regolith so that there is no annual variation) is -35C. If the earth is 15C then that’s 45C to be accounted for by GHG insulation and albedo difference. I understand GCMs all use a static value for albedo and that value varies by some 70% between models. In other words it’s a fudge factor to be adjusted manually to make the model’s output look more like historical observations.
    Observations of earth’s average albedo in real-time are all rather recent and show substantial variation.
    Of course the actual average temperature of the earth is of course the average temperature of the ocean which is about 4C not 15C. The surface today is temporarily much warmer than “usual” if by “usual” we mean the last few million years. The difference between the usual temperature and today’s temperature is almost all due to change in average albedo. The only “tipping point” due to runaway positive feedback is snow and ice cover which, because changing reflectivity of clear sky land/ocean from single digits to close to 90% for snow and ice changes the amount of energy reaching the surface by tens to hundreds of watts/m^2 vs. less than 10 watts for doublings of CO2 from any base point above 200ppm.
    The way I see it any marginal warming we get from any amount of CO2 humans can practically add to the atmosphere is in primary effect an increased margin of safety above the tipping point that ends interglacial periods. I’m an engineer too so we should both appreciate thinking about safety margins. The margin I’m concerned about is the one that keeps the earth covered with liquid water and green plants instead of ice and snow.

  45. Lovely deductive reasoning, but I can’t help but feel there is a danger in considering just one factor (CO2) in isolation.
    The atmosphere as a dynamic and complex mishmash of many forcings, feedbacks etc, so it is really impossible to look at the effect of one on its own.
    If CO2 does have a huge 80C forcing, what negative forcings from methane, water vapour, ozone etc would it take to reduce the overall effect to observed levels?
    And is that an alternate?
    Andy
    PS No I don’t believe Co2 has such impacts (if any) but how to deduce what is really at play – just nature taking its course perhaps?

  46. George E. Smith says: October 25, 2010 at 9:22 am
    So regardless of what H2O does with LWIR (or irregardless, as the case may be); MORE H2O in the atmopshere in ANY and ALL phases ALWAYS reduces the total solar energy that is absorbed by this planet; just as a lower TSI would; and over time that must lead to a cooler planet.
    So just where climatists get off claiming H2O and Clouds as a positive feedback warming mechanism; is beyond me.

    I’m not a climatologist, but I don’t think this is quite right.
    Looking just at water vapor (NOT droplets as in clouds), the water absorbs some IR radiation but very little visible light. (See this previous post here: http://wattsupwiththat.com/2008/06/21/a-window-on-water-vapor-and-planetary-temperature-part-2/ for a graph)
    So the incoming solar radiation is indeed reduced — but only a tiny bit since only a tiny bit of the energy is IR. So instead of ~170 W/m^2 of sunlight absorbed at the surface, maybe it is 169 W/m^2 or 165 W/m^2. That by itself would indeed cool the surface.
    But that is only part of the situation. The earth is trying to radiate that energy back into space in the form of IR. But now the H2O in the atmosphere blocks a great deal of the IR, leading to a warming of the H2O molecules and hence a warming of the air. The more H2O, the more IR gets blocked, and the more the atmosphere warms, and the more it can radiate IR back to the earth. This IR energy back outweighs the little bit of sunlight that is blocked from reaching the earth. (And of course, this is the whole idea of the greenhouse effect.)
    So the net effect is indeed a positive feedback from the water vapor. (I agree that water droplets and clouds would indeed be a negative feedback. )

  47. DesertYote says:
    October 25, 2010 at 12:01 pm
    richard telford says:
    October 25, 2010 at 7:51 am
    There was a similar post to this on WUWT a month or two back. Not surprisingly they share the same flaw.
    The greenhouse effect of 30C is for a planet with an albedo of 0.3. The earth would not be cooler by more than 30C if the atmosphere was not radiatively active because the albedo would increase because of increased snow and ice cover.
    #
    What does a state change discontinuity at boundary have to do with the anything?
    ————————
    @DesertYote: It’s the difference between walking on water and walking in water.
    @Telford: I assume that he meant “all things being equal”, as in equal albedo, the earth would be 30C colder. Since it’s an analysis of formulas, that seems reasonable. Is this going to be a problem for you?

  48. @ Dave Springer:
    October 25, 2010 at 12:20 pm
    I agree with your point that any additional co2 being just a increased insurance against ice if it affects anything at all. It is cold we need to fear.
    I am curious where you got the 4ºC average temperature for the oceans. If that is actual then by 29%x42ºC + 71%x4ºC = 15ºC it would take the land masses to have an average of some 42ºC to average out at 15ºC, way too high. I have always been a bit suspicious of some of these figures tossed about by IPCC and if the four degrees is correct then their fifteen degree average seems clearly wrong. Was it via ARGO?

  49. John
    I read your post once. Understood it well but on the assumption that George E Smith did not make. I respect George a great deal but in this instance I think he mis-interpreted your objectives for the post. I could be wrong of course. I think you were merely demonstrating the flaws in the AGW analyses current available. Telford always pipes up with a strawman and so I ignore George on the other hand is always detailed and cannot be ignored. Your post for me was meant to be simplistic and for that it works.

  50. Tim F says:
    October 25, 2010 at 12:55 pm
    You may have missed the point. It is the 3 phases of H²o that are important. All 3.

  51. I think the “interesting article on the Skeptical Science (SkS)” that you mentioned also suggests the problem with your analysis — feedback.
    The climate sensitivity to CO2 is the affect on global temperatures due to a change in CO2 and the resulting feedback and changes in the earth.
    You said “For example if increasing CO2 caused a forcing of 2 W/m2 and the observed temperature change was 5 °C, then the climate sensitivity would simply be 2.5 °C /(W/m2).” But your analysis then goes on to assume that ONLY CO2 plays a role.
    The very article from SkS that you looked at has a big section titled “Water Vapour as a positive feedback”. In that section, they specifically state “How much does water vapour amplify CO2 warming? Without any feedbacks, a doubling of CO2 would warm the globe around 1°C. Taken on its own, water vapour feedback roughly doubles the amount of CO2 warming. When other feedbacks are included (eg – loss of albedo due to melting ice), the total warming from a doubling of CO2 is around 3°C (Held 2000).”
    The finer points of the magnitudes of the feedback are certainly debatable, but for you analysis, you need to consider that feedback! CO2 is only ~1/3 as important as you suggest, which would suddenly throw all your calculations off and make everything much more reasonable.

  52. Well John, you’ve just proved mathematically what a recent warmist paper concluded from GCM’s: water vapour is an insignificant GHG – it’s all down to CO2.

  53. Interesting.
    Something on this issue is evolving.
    Until last week I had frequent headache. Global temperatures in 1850 are terrible.
    At the moment everything is very simple. It’s on “agenda” … new beginning in 1959 for the future.
    The mathematics of AGW is simple;
    Delta (T) = {[a.ln C / Co] + k [0.35 PDO + 0.87 AAO + pi AMO -sin (Niño 3.4) + 1 / 3 AMO + e (SOI)^4]} * 0 + 2.5 ° C.
    = 2,5ºC
    I love this blog. I have deep respect for all.
    Anyone who read http://www.surfacestations.org/ and add something with 0.2 º C for UHI … … .. Nothing happens to the planet…. (they want to save).
    We have satellites.
    Dr Roy (phd), sorry.
    At launch,
    http://www.spacestations.org .xxx

  54. Vince Causey says:
    October 25, 2010 at 1:34 pm
    Well John, you’ve just proved mathematically what a recent warmist paper concluded from GCM’s: water vapour is an insignificant GHG – it’s all down to CO2.

    That real funny Vince, if you would have carefully read the article it mathematically proved the exact opposite to your comment, CO2 has little significance and it’s all about water. Guess that kind of washed out your point, sorry bout that.

  55. This has been a fascinating read – orignal posting and many of the comments.
    I must say I remain troubled by the thought that anyone could assign a “Climate Sensitivity” to a single trace gas in a rather complex heat engine. It seems to me you would need to remove the effect of clouds, the effects of convection, and the impacts of all other overlapping GHGs (mainly water) and then you could determine a sensitivity to warming – but what good is it since it doesn’t describe the real system?
    The real system pushes back no matter what curve you assign to CO2 – we know this because we are alive today, and we know there was much more CO2 in the atmosphere in the past ages. Had CO2 been the controlling influenece it would have cooked the Earth.
    Also, why is the Earth warming? Until we know why and how natural warming occurs we cannot hope to know why and how unnatural warming occurs. AGW seems to want to ignore natual warming and assigns it as a constant, but it is anything but.

  56. stephen richards says: October 25, 2010 at 1:27 pm
    You may have missed the point. It is the 3 phases of H²o that are important. All 3.

    No, I didn’t miss that.
    The claim was “MORE H2O in the atmosphere in ANY and ALL phases … must lead to a cooler planet.” My point was that more H2O in the atmosphere in the specific phase of water vapor increases the net downward radiation — it blocks a tiny bit of solar radiation from reaching the earth, but it more than makes up for that by radiating IR downward. Thus, adding more H2O vapor must lead to a WARMER planet. As we know, H2O is the major greenhouse gas, so we know that H2O is the single most important gas in keeping the earth ~30 C warmer that it would be without any GHG’s.
    I do agree that adding more LIQUID or SOLID H2O to the atmosphere (in the form of clouds) will lead to a cooler planet do to changes in albedo. In fact, I did mention this in my previous post (but I apologize for overlooking the 3rd phase — clouds can indeed contain solid water, not just liquid droplets). I don’t have the personal expertise to argue whether the warming or cooling is a greater affect — I’ll leave that question to others.

  57. wayne says: October 25, 2010 at 1:01 pm
    I am curious where you got the 4ºC average temperature for the oceans. If that is actual then by 29%x42ºC + 71%x4ºC = 15ºC it would take the land masses to have an average of some 42ºC to average out at 15ºC, way too high.

    4 C would be the average temperature thru the whole depth of the ocean. The surface itself would still be around 15 C. And that 15 C surface temperature is all that matters for IR radiation to the atmosphere. (Kinda like rocks deeper down are much hotter, but that doesn’t affect the IR radiation either.)

  58. “It seems that the choice of wording whether to call water vapor and clouds in the atmosphere forcing or feedback is dependent on what is wanted to be proven.”
    Perhaps, but it would certainly explain why they did their calculations the way they did. What isn’t explained is why the troposphere isn’t warming at the modeled rate of 1.4 times that of the surface.
    Remote Sensing 2010, 2, 2148-2169; What Do Observational Datasets Say about Modeled Tropospheric Temperature Trends since 1979 John R. Christy 1,*, Benjamin Herman 2, Roger Pielke, Sr. 3, Philip Klotzbach 4, Richard T. McNider 1, Justin J. Hnilo 1, Roy W. Spencer 1, Thomas Chase 3 and David Douglass

  59. There is a problem in the argument here that should be pointed out. The forcing due to CO_2 cannot be exactly logarithmic, only approximately so in the region of concentrations not too different from now. In particular this relationship must break down for very low concentrations because otherwise as CO_2 concentration dropped to zero, the forcing would become negative and temperature would go towards negative infinity. You therefore can’t use the logarithmic model to calculate total forcing because that would involve using it in the low concentration region where it is invalid.
    You indeed saw this when you discovered that using zero as your lower limit for CO_2 concentration would give nonsense. Your solution was to use 1ppm as your lower number for CO_2 concentration which gave you a total forcing of 31.9 W/m^2 which you stated gave you confidence because it was close to the 32 W/m^2 claimed in the literature for the total radiative forcing for CO_2.
    But 1ppm is a completely arbitrary number. It happens to look nice in base 10. But the universe doesn’t see anything special about this concentration. If you had used 2ppm or 0.5ppm instead for your lower limit you would have calculated total forcings of 37.25 and 26.55 respectively.
    You see how sensitive the figure is to the choice of this completely arbitrary lower limit. Remember that the only reason for that lower limit to be there at all is because you can’t use zero as it would give a nonsense result of infinity. Observe that the bulk of the effect is happening in this very low concentration region where the logarithmic model has broken down and where there is no reason for us to believe that any of the numbers it generates have any relationship to reality.
    I can only hope that the 32 W/m^2 number for total CO_2 forcing you quote from the literature was NOT computed in this way and that the close agreement in number is purely a coincidence. Because if this is how total CO_2 forcing was actually computed in the literature then that is a scientific scandal as the calculation is a complete nonsense and should never have passed peer review.

  60. “”” Tim Folkerts says:
    October 25, 2010 at 1:53 pm
    stephen richards says: October 25, 2010 at 1:27 pm
    You may have missed the point. It is the 3 phases of H²o that are important. All 3.
    No, I didn’t miss that.
    The claim was “MORE H2O in the atmosphere in ANY and ALL phases … must lead to a cooler planet.” My point was that more H2O in the atmosphere in the specific phase of water vapor increases the net downward radiation — it blocks a tiny bit of solar radiation from reaching the earth, but it more than makes up for that by radiating IR downward. Thus, adding more H2O vapor must lead to a WARMER planet. As we know, H2O is the major greenhouse gas, so we know that H2O is the single most important gas in keeping the earth ~30 C warmer that it would be without any GHG’s. “””
    Well Tim the polite response to that statement is that it is nonsense. The absorption of solar spectrum energy by H2O vapor in the atmosphere commences at about 750 nm wavelength in the red portion of the spectrum, and then therre are a number of H2O absorption bands that occur out to the 4.0 micron region. Teh solar spectrum contains about 45% of its total energy beyond 750 microns, and only 1% beyond 4 microns; so there is 44% of the total solar energy in that range; and water vapor bands might actually acount for about half of that. Which is why the extra-terrestrial TSI of 1366 W/m^2 gets attenuated to a clear sky air mass one level of about 1,000 W/m^2.
    So your characterization of the H2O vapor “blockage” as being “tiny”; is simply not an accurate depiction; it is one of the largest solar spectrum modifications caused by the atmosphere. Solar spectrum energy mostly goes deep into the oceans which reflect only2-3% of sunlight; and the part of the earth which is mostly oceans is in the tropics where most of the solar energy arrives.
    True; that absorption by the the H2O in the atmosphere does warm the atmosphere; in fact it is one of the major warming influences; and that results in long wave Ir radiation in an isotropic pattern so only half of that radiative LWIR energy comes down to the surface. The other half goes upwards to space; so there is a net energy loss to the surface of about 1/2 of the amount that H2O vapor absorbs from the solar input. Reducing the total amount of solar energy that reaches the earth surface ALWAYS results in it getting cooler.; that can be seen instantly in a partial eclipse of thes un; or standing in the shadow zone of a cloud. There is no H2O vapor, liquid or solid phase phenomenon anywhere in the atmopshere where an increase in water results in an increase in the ground level solar energy.
    Earth to Tim ! This planet has almost no other external energy input besides solar spectrum electromagnetic radiation from the sun; sunlight. Any reduction in sunlight for time scales of climate significance must result in a cooler earth.
    Now to your downwelling LWIR.
    Apart from direct atmospheric heating from absorption of solar energy, you have conductive and convective heating directly from the surface; and you also have some LWIR thermal emission (radiation) from the warmed surface. That energy was already part of the soalr input energy that warmed the surface in the first place; so it is nOT a new source of energy; it is old energy that has been thermally degraded by shifting from the 0.5 micrn centered solar spectrum to the 10.1 micron centered earth emission spectrum corresponding to a 288 K mean surface Temperature, and though it was of the order of 1,000 W/m^2 (max) when it entered; it is now only 390 W/m^2 qaas it proceeds upards and some of it is captured by the various GHGs including H2O; and that too warms the ATMOSPHERE by collision thermalization. That warm atmospehre in turn radiates isotropically in a thermal spectrum commensuratew ith the atmospheric Temeprature; just as before with the solar heating; and once again, only halkf of that emission can return to the surface; and that too is energy that has already been accounted for as part of the incoming soalr energy.
    To the extent that solar energy input is curtailed by H2O absorption or cloud albedo reflection plus absorption, the ground must cool, and the amount of outgoing LWIR radiation to heat the atmospehre must also decline; as will the amount of secondary LWIR emission from the atmospehre that reurns to the surface.
    Downward radiation from the atmosphere is in the 5-80 micron spectral range (98% of it); rather than the 20 times shorter 0.5 to 4.0 micron range of the original solar spectrum energy. That spectral shift has a major consequence; instead of penetrating to the deep oceans (tens to hundreds of metres), as solar energy does, the LWIR makes it all the way through the top 50 microns of the water surface (2/1000ths of an inch); which is five times the 1/e attenuation depth of 10 microns and accounts for 99% of the enrgy absorbed.
    That energy absorbed in just the surface layer; reults in very localised heating of the surface and prompt evaporation of H2O; whcih then transports massive amounts of latent heat of vaporization into the atmosphere which convects to the upper atmosphere where it is deposited by condensation; and possibly freezing; about 545 cal per gram plus another 80 if it freezes..
    So very little of the downward LWIR energy remains in the oceans; most of it returns quickly to the atmospehre in a massive heat transport to higher altitudes (moist air is lighter than dry air.
    How you make a total net warming if you have more H2O in any phases, let alone all three is quite beyond me.
    There is no other significant energy input to the earth (from outside) besides SUNLIGHT. H2O in ANY form ANYWHERE in the atmospehre ALWAYS reduces the ground level sunlight; there are NO EXCEPTIONS TO THIS RULE.
    Ultimately, it is the total solar energy that EARTH ABSORBS that determnines its Temperature over climate times scales.=; and H2O ALWAYS reduces that.

  61. “”””” Tim F says:
    October 25, 2010 at 12:55 pm
    George E. Smith says: October 25, 2010 at 9:22 am
    So regardless of what H2O does with LWIR (or irregardless, as the case may be); MORE H2O in the atmopshere in ANY and ALL phases ALWAYS reduces the total solar energy that is absorbed by this planet; just as a lower TSI would; and over time that must lead to a cooler planet.
    So just where climatists get off claiming H2O and Clouds as a positive feedback warming mechanism; is beyond me.
    I’m not a climatologist, but I don’t think this is quite right.
    Looking just at water vapor (NOT droplets as in clouds), the water absorbs some IR radiation but very little visible light. (See this previous post here: http://wattsupwiththat.com/2008/06/21/a-window-on-water-vapor-and-planetary-temperature-part-2/ for a graph) “””””
    Tim you need to aquaint yourself with any of the standard widely available graphs of the Solar Spectrum, outside of the earth’s atmospehre hwere it fairly closely approximates a Black body Radiation curve corresponding to about a 5800 K BB Temperature. It show that about 98% of that energy lies between about 250 nm in the UV and 4.0 microns; with the remaining as 1% left over at each end. Such graphs often have superimposed on them the actual ground level (air Mass once) spectrum; that shows the amounts of that energy taken out by primarily O2, O3, and H2O, in the case of H2O which absorbs in the visible and near IR perhaps 20% of the total solar energy is capture by water VAPOR (clear sky) clouds are an additionqal loss over and above that.
    I can’td raw those graphs with my keyboard so go to wikipedia or some science source and find them.
    ONE THING THAT ANTHONY COULD DO TO ASSIST HERE IS PUT THOSE SOLAR SPECTRUM GRAPHS ON THE SIDE WITH HIS OTHER CLIMATE GOODIES SO THAT EVERYBODY HAS THOSE CURVES ENGRAVED ON THEIR FOREHEAD.
    You can’t talk sensibly about the physics of climate if you don’t ahve a mental picture of the solar spectrum in outer space, and at the earth surface in front of you at all times; then a 300 K (or 288 K) thermal BB spectrum corresponding to surface emission would help too.
    It takes far too many words to describe the general characteristics of Black Body radiators and absorbers; and anybody who doesn’t think the earth is near black body over most of its surface (the deep oceans) just hasn’t thought about it. If it wasn’t for the blue scattering of sunlight in the atmospehre; the earth would look MOSTLY BLACK from outer space; the oceans are not green or blue; they are black (deep oceans) 97-98% goes in and never comes out; only 2% is reflected at normal incidence, and about 3% over the range of sun angles and wave tilts.

  62. Ian,
    The cited reference is where the 32 W/m2 came from which is based on empirical data. I played around with the lower numbers as you mentioned and got comparable results. I am assuming that the equation was calibrated to about 1 ppm which is why using it worked in the manner that it did.
    As for various comments asking why the Earth is warming.. The Earth is always changing temperature. It generally has a long term (1,000 year+) trend, but in the short term (<200 years) it is highly variable.
    All paleoclimate data shows that type of variation. Except perhaps tree ring data.

  63. “Without the atmosphere the Earth would be around -15 °C and with the atmosphere it is currently about 15 °C. That 30 °C difference is caused by the insulative effect caused by the atmosphere.”
    It would be helpful to me if you clarified what you mean by the Earth being 15 °C. I always figured that that number was just the earth’s surface *air* temperature (at sea level). Air temperature, of course, is the temperature that is most easily and commonly measured but wouldn’t the Earths true temperature (near the surface) be lower if you took ocean temperatures into consideration?

  64. “”” jorgekafkazar says:
    October 25, 2010 at 9:52 am
    George E. Smith says: “…Try drawing a STRAIGHT LINE between the 315 and 390 ppm points on your two graphs; and now try to sell me that the scattered data better fits the log curves than it does the straight line linear curves…”
    A straight line will approximate the curve for small increments of CO² concentration. This does not disprove the logarithmic nature of the overall correlation. “””
    Perhaps I didn’t make myself clear.
    The idea is to take John’s logarithmic curves; then add the the 315 to 390 ppm straight line segments I suggested; then superpose the actual 52 year observed Mauna Loa CO2 values, along with your favorite mean Global Temperature (anomaly) graph; either GISStemp, HADCrut, RSS or UAH values; and then propose an argument as to why the data supports the logartihmic cuves rather than the Linear curves. You will find the data supports neither the straight line nor the logarithmic models; not is there any other continuous mathematical function you could propose (with no more than 52 arbitreary parameters); which would fit the data in any cause and effect believable way; and I will allow you to propose any tiem offset between the CO2 values, and the Temeprature values (in either direction) in order to improve your fit to the data.
    Have at it.
    By the way; I AM NOT knocking John’s essay or analysis; I haven’t fully digested it yet. I’m just pointing out from an initial scan; that it assumes a result that is “not in evidence” as the lawyers would say; namely a logarithmic relationship between mean earth surface Temperature, and the log (base two) of the CO2 amount. As in:-
    T2 -T1 = (cs) log2(CO2,2/CO2,1) or some facsimile of such an equation. if the notation of that equation is not self evident; then ask a friend to explain it to you.
    And that unprovable logarithmic relationship is the central tenet of climate science; it is to climate science what the velocity of light or the rest mass of a proton is to ordinary Physics; and it appears to be known; according to the IPCC to the startling accuracy of =/- 50%, whcih gives a 3:1 range form 1.5 deg C to 4.5 deg C per doubling.
    And Dr Judith Curry; in her recent Scientific American interview allows that it could be between 1 and 10, rather than 1.5 to 4.5.
    Not my idea of settled science.

  65. By the way, I wish people would stop assigning significant albedo contribution to snow and ice cover (mostly in te polar regions) rather than to cloud cover which averages about 61% on earth (cloud cover, not albedo)
    There is a very good reason why there is snow and ice at the poles. THERE’S VERY LITTLE SOLAR IRRADIANCE THERE. So regardless of the reflectance of snow and ice; which isn’t all that great except for very fresh snow; not much solar energy is reflected from there because there isn’t much to begin with.
    Yes some like to point out that in summer you get sun 24 hours a day; but it is spread out over a huge surface area because of the obliquity; so it is a small portion of earth’s albedo.
    So if clouds were eliminated by removal of H2O from the atmosphere the albedo would most certainly go down drastically; it won’t go up. Yes if it got colder in mid latitudes you’d get more snow in wintertime, which would for a while have more albedo contribution; but the clouds that precipitate that snow would have a bigger albedo effect. Snow more than 72 hours old is not very reflective; because of surface melting, which makes it optically transparent (at solar spectrum wavelengths), and the sunlight once it getsinto the melted snow structure gets trapped in ther by optical Total Internal Reflection. You can wiki that for yourselves to get an explanation; I should not have to explain Total Internal Reflection to anyone with more than an 8th grade science education. (yes I DID learn it before the equivalent of 8th grade.) In those days; you were supposed to learn stuff in school; rather than just feel good about yourself. earth’s clouds are far and away the major source of its albedo; not snow and ice.

  66. Tim Folkerts
    “(Kinda like rocks deeper down are much hotter, but that doesn’t affect the IR radiation either.)”
    It would be nice if you could expand on that sentence. I have things figured differently. The presence of heat in rocks deeper down and coming upward from internal heat sources makes the cold pool of the deep ocean more worthy of consideration. To me it seems that some of earths heat as it exists on the surface must be continually extracted from the depths by some ocean circulation process. Just guessing I would think polar oceans must be sinking cold water. If so I would say that the cold temperatures of the deep ocean do indeed come from the surface and therefore those temperatures would need to factor into average surface temperature calculation.

  67. Couldn’t you derive a firm sensitivity figure from using the amount of forcing the Sun provides to a point on the day side of Earth, and comparing it to the lack of forcing on the night side of Earth? dT/dF? If you can do it this way, the figure is quite low. If not, can someone explain why not?

  68. Hmm, not sure my point was clear. I mean take the average change in temperature, and divide that by the change in forcing from the sun from maximum exposure to the sun to minimum exposure to the sun. Still not sure I am being clear, I hope so.

  69. John Kehr
    Sorry about being skeptical on your calculations, but I need you to consider this:
    At first using the alamist numbers you attributed 86% of the GHE on CO2 forcing. But that is excactly what they say – they say clouds and water wapor are only feedbacks which are dominated by CO2. So what your calculations mean is that if their assumptions about CO2 as the driver and water wapor as the engine are correct, the climate sensitivity estimates are also correct.
    Or am I missing something here?

  70. Doug Proctor says:
    October 25, 2010 at 8:24 am
    The place where distrust and acrimony will live is in the literate but non-professional arenas such as WUWT. We need to find some foe, if not friend, to sit at the table and engage in discussion.
    Is there anyone out there or are we more victims of the two solitudes?

    There is a small amount of interaction going on between my site and that of scientistofdoom regarding the (in)ability of ‘back radiation’ to warm the oceans at the moment. Dialogue is good, between people who regard each other as equals, at least intellectually.

  71. Missing one big piece of information, where does the original forcing figure come from. From the global circulation models with no apparent justification other than trust us???

  72. It might be instructive for people wondering how the greenhouse gas process affects the atmospheric Temperature to look at a simple case of another kind; and you can get an adequate picture of this from Wikipedia.
    The somewhat similar case would be the relatively simple mechanism of the Helium Neon Laser. Everybody knows that the He-Ne laser emits a red line at 632.8 nm; which results from an electron transition of the Neon atom. Well actually it can also emit a nice infrared line at 3.39 microns and another one at 1.15 microns, both of which are Neon emissions. Well these days you can also get a green He-Ne laser.
    So what the hell is the Helium for. Wiki shows how this all works. To get the Neon to lase; you have to “invert the population” of electrons in certain states of the Neon atom; and the ones you play with determine which wavelength is emitted. The actual wavelength selection is done with spectrally selective mirros on the cavity mirrors; that are high reflectance for the chosen line; but poor reflectors for the wavelengths you don’t want; but that has nothing to do with the Helium.
    The electric discharge in the tube is basically a discharge in ionised Helium; which requires lower energies than NEON. So you end up with Helium ions which are in some higher energy states, and they are above the energy levels that you want to populate in the Neon atom system. So this is akin to the way CO2 can absorb a photon in the 15 micron range and excite the bending mode of the CO2 molecule.
    The Helium excited ions, NOW COLLIDE with neon atoms; and energy is conveyed to the Neon atom via a phonon transition which is a mechanical quantum of energy ( heat), and that phonon reaction is what transports the original electric energy to an excited inverted population of neon atoms. So that is directly analagous to the transfer of energy from the CO2 molecule (or other GHG) to the ordinary N2, O2, or Ar molecules of the atmoshpere; those too are analagous to phonon transitions; where momentum is exchanged along with energy; but no Photon is involved. This energy conveyance via phonons, results in warming the atmosphere; there really isn’t photon transport from the CO2 to the N2/O2/Ar.
    Once the atmospheric gases are warmed to a higher Temperature by this energy shift from the GHG to the atmospheric gases; then the normal black body like thermal radiation of infrared Photons can take place from the atmosphere to give the downward (and upward) LWIR thermal radiation from the atmosphere; which depends only on the atmospheric Temperature.
    In the lower density and cooler ionosphere, as Phil has pointed out, the mean free path between molecular collisions is now long enough that the original excited GHG molecules can and do spontaneously decay, with the emission of a photon that is characteristic of the GHG energy level structure; and not black body like dependent on the Temperature; well it will have a Doppler line broadening that depends on the square root of the Temperature (K).
    And as far as I know the thermal EM radiation is explained pretty much completely in classical Maxwell’s equation electromagnetic wave theory; due to the acceleration of electric charges which in turn is a consequence of the Temperature; and the momentum changes that occur during collisions. The only quantum aspect that needs to be added is what Planck did; which was to simply insist that each mode of oscillation had only a quantized energy (multiple of kT); whereas the earlier Raleigh Jeans derivation assumed that the oscillator energy could be any continuous value; and that led to the so-called Ultra-Violet catastrophe that predicted very high spectral radiance at ever shorter wavelengths.
    But Planck’s little change fixed the whole problem, in one of the crown jewels of modern Physics (BB radiation theory); and in a way largely started the whole quantum ball rolling. But the derivation of BB spectra involves NO atomic or molecular electron energy level structures; only that the energy assigned to each degree of freedom be an integer multiple of kT.
    So look at the Wiki He-Ne explanation, and it will give you an idea of how a not unlkike process works in the GHG picture.
    Enjoy !

  73. “Teh solar spectrum contains about 45% of its total energy beyond 750 microns, and only 1% beyond 4 microns; so there is 44% of the total solar energy in that range; and water vapor bands might actually acount for about half of that. Which is why the extra-terrestrial TSI of 1366 W/m^2 gets attenuated to a clear sky air mass one level of about 1,000 W/m^2.”
    Point well, taken. I did underestimate the total amount of energy in sunlight in the IR band — even though the intensity is low, the tail is rather broad and includes a good chunk of the energy in the solar spectrum. I also underestimated the amount of IR absorption by water in the near IR. So rather than a ~2% of the energy getting absorbed on the way in by H2O as I suggested, the number is actually closer to ~20%.
    I don’t think that changes my overall conclusions, though.
    For one thing, that IR energy is STILL absorbed by the atmosphere, not reflected as clouds do for visible light. Hence it still gets added to the heating of the earth as a whole (albeit in the atmosphere, rather than on the surface).
    Or put another way, the atmosphere is blocking ~67 W/m^2 of IR (that ~20% you mentioned) that fails to reach the surface due to absorption by various GHG’s along the way. But GHG’s add extra ~342 W/m^2 of downward IR to the earth’s surface. Get rid of H2O (and CO2 and CH4 …) and you add back that 67 W/m^2 — but you lose the 324 W/m^2!
    Or simply consider that the blackbody temperature of the earth (without atmosphere) in equilibrium with the sun is WAY colder than the observed temperature. As stated in this very blog: “Without the atmosphere the Earth would be around -15 °C “. Dave Springer claimed in his comment that the moon is around -35 °C. Either way, the temperature of the earth with no atmosphere would be WAY colder than it is.
    The only way for the earth’s surface to be warmer than that is for other radiation to be reaching it. (OK, there is a tiny bit of geothermal energy working up to the surface, but the estimates I have seen for that are around 0.1 W/m^2 so that really don’t matter. Or warm air could be warming the earth by conduction, but that seems too absurd to contemplate since the vast majority of the atmosphere is COLDER than the surface — the overwhelming consensus is that the atmosphere COOLS the surface thru convection.)
    So where is this radiation coming from if not the atmosphere? And where in the atmosphere is it coming from if not the major greenhouse gas, H2O?
    I can’t see any way to escape the logic that more water vapor (and more GHG’s in general) should and do have a net affect of warming the planet.
    (Again, other feedback certainly affects the system — like perhaps more water vapor –> more water droplets –> more clouds –> higher albedo –> cooling. But that is a different and more complex topic than I think we are discussing.)

  74. George E Smith
    Thank you for your contributions. This has been my thought on this subject for a while now. Though, I would certainly be less eloquent in my presentation. That is, based on the observed data climate sensitivity is neither linear nor continuous. In fact, there is no guarantee that even if we can know the climate sensitivity at a given time and place that it is repeatable.
    PS: Are you THE George E Smith, Nobel Laureate in Physics?

  75. Doug;
    It is one of the burdens of my existence that since late 2009, I have had to issue disclaimers to the effect that I AM NOT The George E. Smith who was last year’s Nobel Prize winner in Physics; but I know of him although I have never personally met him. He was at Bell Labs; where he did his Charge Coupled device (CCD) research; while I was VP of R&D for what was at one tme the largest LED company in the world (which we started from a kitehcn table). Every time I went to an industry conference, I would find I was already registered; but it was the Bell Labs chap.. It turns out that the diretor of R&D for Beckman Instruments at that time was also a George E. Smith;I’ve not met him either.
    Then there was a George Smith who was a 19 year old sailor on the Battleship Oklahoma during the attack on Pearl Harbor; and that was the ship that rolled over and trapped a lot of sailors underwater. They eventually saved a great many of them by cutting holes in the hull of the ship which took several days.
    George Smith dived off the deck as it was rolling over, and narrowly missed getting squished by the superstructure as it came down. He swam ashore to Ford Island with very few others, under a sea of burning fuel oil through which he had to periodically surfaced, and got horribly burned; but he survived and I think is still alive today; and he has an Oklahoma survivors web site. Check it out; it’s an inspirationalk story.
    I can’t claim any achievement that matches that.

  76. HankHenry says: October 25, 2010 at 3:55 pm
    Tim Folkerts “(Kinda like rocks deeper down are much hotter,
    but that doesn’t affect the IR radiation either.)”
    It would be nice if you could expand on that sentence. I have things figured differently. The presence of heat in rocks deeper down and coming upward from internal heat sources makes the cold pool of the deep ocean more worthy of consideration.

    I actually hadn’t given it a lot of though, but here is my understanding after musing a little while.
    Overall, there is about 0.1 W/m^2 of geothermal energy working its way up (at least from estimates I have seen — for example http://en.wikipedia.org/wiki/Geothermal_gradient). This is a pretty small number on most scales associated with global temperatures.
    In the absence of any other heat sources or sinks, there will be a gradual warming the farther down you go. Themal energy moves only upward via conduction in solid rock of the crust — deep mines are always warmer than the surface.
    However, the temperatures in the deep ocean are governed primarily by convection. Ice cold water from near the poles sinks and is carried along the bottom of the oceans. This apparently is a much bigger heat sink than the average 0.1 W/m^2 heat source of geothermal energy coming up from the bottom (I haven’t done the calculations, but it seems entirely plausible). Hence the geothermal energy cannot warm the water much and it remains icy cold.
    (Of course, the this is just a side point of a side point — the more important point was that neither the hot rock a mile down nor the cold water a mile down affects the IR radiation from the surface.)

  77. John Kehr says:
    So according to the accepted climate sensitivity and CO2 forcing equations, CO2 accounts for 86% of the total GHE.
    And yet, over at Skeptical Science where you lifted the radiative flux figure of 32W/m2 for CO2 from, in the very same sentence:
    The greenhouse effect or radiative flux for water is around 75 W/m2 while carbon dioxide contributes 32 W/m2 (Kiehl 1997).
    it attributes a value of 75 W/m2 for water vapour. So… when the portion of the GHE attributed to water vapour is obviously over 2x that of CO2, how the heck can CO2 account for 86% of the GHE?
    There are numerous other outrageous howlers in your ‘analysis’ (Ian H already pointed out that the logarithmic equation you are using for CO2 forcing completely breaks down for small values of starting CO2), but they will have to wait till tomorrow as it’s getting late here.

  78. Should we add some climate sensitivity feedback math to the discussion?
    The Clausius-Clayperion equations say that specific humidity increases 7% for each 1.0C in temperature.
    – CO2/GHGs doubling causes +3.7 Watts/m2 extra forcing which increases the tropopause temperature by 1.0C and the surface temperature by 0.68C so humidity levels should increase 7% at the tropopause and 4.5% at the surface.
    – Given the last GISS study, we can take 75% X 150 Watts/m2 X 4.5% (water vapour feedback based on its percentage of the greenhouse effect) and we get +5.0 Watts/m2 from water vapour feedback.
    Calculations from the same Clausius-Clayperion equation says that cloud cover should increase by about 2% for each 1.0C. Increased cloudiness by 2% will change the Solar forcing by about -0.4 watts/m2.
    There will also be some Ice Albedo feedbacks but the temperatures have to rise by a big enough number to make alot of difference in these numbers (it is already a low number since the majority of the Ice is above 75N). Given some of the numbers from below, I would estimate a reduction in Albedo of 0.004 (I have a model for Albedo and have played around with it enough to say this is probably close) which would result in an increased Solar forcing of +1.0 Watts/m2.
    So, we have GHG forcing and the feedbacks for the Surface of:
    = +3.7 Watts/m2 CO2/GHG forcing;
    = +5.0 Watts/m2 water vapour feedback;
    = -0.4 Watts/m2 increased cloud feedback; and,
    = +1.0 Watts/m2 reduced Ice Albedo feedback.
    = +9.3 Watts/m2 = +1.6C per doubling.
    I have ended up at about this same number using four different methods now.

  79. I made a little mistkae in the above at 6:10 pm, the 2% increase in cloudiness should result in -1.0 watts/m2.
    So, we have GHG forcing and the feedbacks for the Surface of:
    = +3.7 Watts/m2 CO2/GHG forcing;
    = +5.0 Watts/m2 water vapour feedback;
    = -1.0 Watts/m2 increased cloud feedback; and,
    = +1.0 Watts/m2 reduced Ice Albedo feedback.
    = +8.7 Watts/m2 = +1.5C per doubling.

  80. Mike Borgelt says:
    October 25, 2010 at 2:37 pm
    wayne says:
    October 25, 2010 at 1:45 pm
    Wayne, I think Vince very firmly has his tongue in his cheek there.

    Well I’ll put Vince on my ‘know’ list, thanks. Just didn’t recog the name and couldn’t let that influence someone not in the scientifically know, thinking this article was all wrong. (That’s my usual approach only because there are thousands just reading and not that familiar with the people and the lingo and, yeah, hidden sarcasm. Vince, that was good! Fooled me. )

  81. @ Tim Folkerts: Got that, thanks. And he is right, over long periods that is basically the correct mean temperature of this climate system to use smoothing out weather and the decades. I see now whereDave was coming from.

  82. “”””” Tim Folkerts says:
    October 25, 2010 at 5:15 pm
    ………………………………
    Or simply consider that the blackbody temperature of the earth (without atmosphere) in equilibrium with the sun is WAY colder than the observed temperature. As stated in this very blog: “Without the atmosphere the Earth would be around -15 °C “. Dave Springer claimed in his comment that the moon is around -35 °C. Either way, the temperature of the earth with no atmosphere would be WAY colder than it is. “””””
    Well sorry to disappoint Tim; but that simply is not correct. Wthout the atmosphere; there are no clouds, and no O2/O3/H2O/Co2 absorption of of incoming sunlight so the ground level solar insolation would be 1366 W/m^2, rather than 1000 W/m^2. and the equilibrium black body Temperature would become 275.7 K instead of 255K
    That is 2.5 deg C above freezing rather than -18 deg C and that is quite without any greenhouse effect whatsoever. There would be no snow deposited on either the mountains, or the antarctic continent, or the arctic ocean ice, and the reflectance of aged ice is way less than fresh snow; so you can count on the albedo contribution of the polar regions going down from its present low level; and that will further increase the result of the increased solar input; because even more of it would be absorbed by th earth than with the present amount of ice albedo which is small compared to the cloud albedo.
    Laci and Scmidt seem to forget the clouds are the major part of earth’s albedo, and they ignored the fact that the 255 K BB equilibrium Temperature at earth orbit, is caluclated assuming that 0.3 total albedo which goes away if water disappears from the atmosphere, and certainly if there is no atmosphere. The total physical, and chemical properties of H2O in all its phases along with some biological effects, is the controlling factor of earth’s comfort Temperature range.
    I could calculate how much it could actually change with CO2 if I had those joker’s supercomputer and a model that didn’t start with declaring H2O to be simply a positive feedback amplification of CO2 as well as clouds.
    As it turns out, over at c-r just a few weeks back, Peter Humbug stated that he had in fact removed ALL of the H2O from the atmospehre on his play station; and he got it all back in just three months. that doesn’t support the laci conclusion that water would collapse irreversibly .
    The paper by Wentz et al demonstrates that the temperature H2O relationship is a very large negative feedback stabilizing effect.
    Interestingly; Bill Illis just posted somewheres hereabouts that Clausius-Clapeyron predicts a 7% increase in specific humidity for a one deg C surface Temperature rise. Interestingly Wentz et al found from satellite measurements that a one deg C rise results in 7% increase in evaporation, precipitation and total atmospheric water. I conjectured from that a similar increase in cloud cover to go along with the increased precipitation.
    In contrast, the GCMs (according to Wentz) agreed with the 7% increase in total water; but said evap/precip (which must match) only increased by 1-3 %. That is as much as a seven x difference between actual measured real world data, and the computer models which can’t seem to get water modelling including clouds correct.
    I’ve asked Lacis to explain; but so far no response; that happens a lot; I post something which just drops into a black hole.

  83. richard telford says: October 25, 2010 at 7:51 am
    There was a similar post to this on WUNT a month or two back. Not surprisingly they share the same flaw.

    This seems to be similar to describing the starter motor is the most important part of an automobile. Without it the car is just a hunk of expensive metal.
    There is a long chain of events going back 4.5 billion years that gives us our atmosphere and its characteristics today. Since the planet had a CO2, N2 atmosphere before photosynthesis in plant life changed it to the O2, N2 version we have today. Past ice stages of the planets history happened in spite of the remaining CO2 in the atmosphere.
    Sure, there may be a “tipping point” where if CO2 and other persistent green house gasses reach a low enough level that atmospheric moisture may be lost to surface ice and an new Ice Age begun. However, that is for low levels of CO2. The point in contention is what happens when persistent green house gasses increase from today’s levels.
    Once our automobile engine is running, the starter motor is just along for the ride.

  84. George E Smith;
    I just had a rant on another thread about the same issues. Well not exactly the same. Your included all the math anda few more points. Couple to add.
    1. There’s not such thing as radiative forcing from CO2. Its like centrifigul force. Everyone uses the term, but it doesn’t exist. Centripetal force exists, and CO2 in theory resists the escape of energy to space. There’s no 3.7 watts/m2 being “forced” into the system at the top of the atmopshere. CO2 is distributed throughout the atmosphere, and an upward bound photon can be absorbed and re-emitted in a random direction, some of which is back toward earth, at any altitude. So the RESISTANCE to earth’s radiance escaping to space is distributed from surface to TOA. No force outward on a body travelling in a circle and no forcing at TOA.
    2. For those jumping all over water vapour being a positive feedback, read George’s retorts on the matter, they are well founded, but add this thought experiment. At sea surface at 15 C, water vapour is 30,000 ppm or so. As you climb in altitude, it gets colder, and cold air can’t hold as much water vapour, so the concentration falls off the higher you go. Imaging a slice of atmosphere really thick with water vapour at the bottom, but really thin at the top. Now imagine CO2. Its spread pretty much evenly from top to bottom at a teeny tiny 280 ppm. POOF is suddenly doubles. What happens? Well some of those upward bound photons that made it past the water vapour at the bottom and used to escape to space clunck right into them, get absorbed, and some get re-emitted back toward earth. About 3.7 w/m2 worth of them. Now here’s the important part. They don’t start from the TOA. Some of them get absorbed and re-emitted a millimeter above the surface, and some at a meter and some at 500 meters and so on. So now there’s 3.7 w/m2 more downward photons than there were before, their “source” being spread out across the entire range of altitudes where CO2 exists. Now here’s the other important part. The earth starts to warm up, meaning more water vapour, mostly at low altitudes where most of the water vapour is in first place. Does it absorb and re-emitt upward bound photons from the earth’s surface, thus increasing the RESISTANCE to photons leaving the planet? Why yes it does. But those darn water vapour molecules don’t actually know up from down and neither do the photons. So, since most of the CO2 is distributed ABOVE most of the water vapour, some of the photons that CO2 sent back to earth wind up hitting all that water vapour instead which absorbs and re-emitts it in a random direction, sending some of it back upward. Ooops, negative feedback. Wait! All that extra water vapour doesn’t just absorb and re-emmit photons sent back down by CO2, it does the same to photons sent back down from Ozone, Methane, clouds and anything else in the atmosphere that tries to send some of the photons back. So more water vapour is a negative feedback to ALL the GHG RESISTORS.
    That being the case, seems to me the concept of water vapour being nothing but a positive feedback has been torpedoed by the randomness of photon emissions. This may have practical use some day for building photon torpedoes, but that’s WAY in the future when we’ve stopped being so sensitive about climate.

  85. Tim Folkerts
    “Of course, the this is just a side point of a side point”
    Not sure I agree with you. If water in polar seas cools at the surface (presumably by radiating heat into the black of space) and then sinks, isn’t that an IR heat loss that is then represented in the cold waters of the deep.
    I imagine the earth as an internally warmed body which is cooled at the surface by the dark of space. In other words a body with a temperature profile that goes from high temps at the center to cool at the surface. It strikes me as odd that while that is the profile for continents the profile for oceans must be something like …. rising temps to the ocean floor then a significant temperature drop at the depths of the ocean and then a re-rise of temps at the surface. It makes me believe that the earth creates huge amounts of arctic temp. seawater at the poles that it then slips underneath the ocean surface at all latitudes. The fact that continental rock at oceanic depths is quite hot just makes me think that this deep ocean cold is even more significant part of what should constitute the Earth’s “average” surface temperature. … remembering that the heat storage capacity of water in its liquid state has a much greater heat capacity than air.

  86. I still don’t understand why you can’t use one spot on the globe as a reference point, and sort out the sensitivity from there. Use the difference in forcing from the sun between day and night. Why does this not work? It must not, or it would have been done already. Unless it falls in that range of things that are too simple, like looking for the car keys that are in your hand already. But I doubt that. Why wouldn’t this work if you used averages? That is what climate science is all about, after all.

  87. One point that really bugs me about virtually every paper, post and comment I have ever seen on climate sensitivity and/or the earth’s energy budget is that everyone assumes that these issues can be satisfactorily explored on the basis of a static model. It is assumed that day and night, variations in TOA insolation due to the earth’s elliptical orbit, seasonal changes due to the inclination of the earth’s axis , and variations in the energy budget due to geographical location ,can all be averaged out without any impact on the analysis. Nowhere have I ever seen any proof that this assumption is valid, or even a reasonable approximation.

  88. Excellent again. Even if this wouldn’t be a scientific paper in itself, it would most certainly make a good critical reply to one, and one they would most likely have to tackle…

  89. Jeff L says: October 25, 2010 at 11:56 am
    “I would love see a warmist post on here an analysis of why this is not a correct analysis.”
    Hi Jeff. The analysis is flawed. Please refer to “Tim Folkerts says: October 25, 2010 at 1:34 pm” for a simple exposition as to why.

  90. George E. Smith says: October 25, 2010 at 8:40 pm
    Well sorry to disappoint Tim … the equilibrium black body Temperature would become 275.7 K instead of 255K.

    Actually, you don’t disappoint at all! Quite the contrary, you provided some great info to think about.
    I should amend my statement to be “As stated in this very blog: “Without the atmosphere the Earth would be around -15 °C “. Dave Springer claimed in his comment that the moon is around -35 °C. George claimed the temperature would be as high as +2.5 C. In any of these cases, the temperature of the earth with no atmosphere would be WAY colder than it is. ”
    I was trying to avoid dealing with specific temperatures, because the estimates do indeed vary. A big part of that is because it is difficult to do the thought experiment “remove all the atmosphere with other things being equal”. 🙂
    What ever assumptions you make about the surface of the earth in that scenario make a huge difference in the final result. I was trying to avoid that whole issue by simply going with “much colder” because that much seems to be pretty much certain.
    One other detail that would seem important is the emissivity as a function of wavelength. Unless I am badly mistaken (which has been known to happen), if the earth has high emissivity for visible light, but low emissivity for IR (ie it absorbs visible light from the sun well, but emits its own IR poorly) then the temperature would end up ABOVE the pure BB temperature. Conversely, if the earth has low emissivity for visible light, but high emissivity for IR then the temperature would be BELOW the pure BB temperature. If the emissivity was the same for all wavelengths, then the temperature would be at the BB temperature.
    From a quick look around the web, the second scenario (below BB temp) seems to fit data I saw, but I am certainly no expert on IR spectroscopy.

  91. How much of CAGW theory is based on the “T” factor of energy in the atmosphere?
    I see it basically like a freeway. If the incoming traffic (TSI) is constant, but the speed of certain cars reduced by the cops (GHG) the total traffic, (energy/ temperature) increases.
    In the above the atmosphere is the freeway, and the TSI is incoming traffic. GHG are the cops that slow down certain red sports cars, (LW radiation) thus increasing the energy or density of traffic on the freeway. However, our earth has more then just freeways. We have many side streets that reduce the speed (residence time of incoming radiation) of traffic more then anything on the freeways. (atmosphere),
    These slower streets are the land and Ocean, and what happens here effects the residence time (speed) of vehicles more then what happens on the freeways. A photon of SW radiation entering and penetrating the ocean slows down dramatically compared to the freeway of the atmosphere. So the total traffic flow (earths energy budget) depends on the time spent on all streets, not just the freeways, or atmosphere.
    If water vapor and clouds increases in the atmosphere, (more cops enter the freeways)
    less traffic enters the side streets, the oceans, and even though freeway traffic increases due to more freeway cops, side street traffic is more sparse (cooling) and total time in the traffic system is reduced even though the freeway traffic is temporarily increased.
    I am just s trying to wrap my non science educated brain around this so any thoughts helping me see if I am driving in the right direction here are appreciated.

  92. The author doesn’t even understand the first thing about what a doubling of CO2 actually means. Tom Kehr says in the original post:
    So all other factors in the Earth’s climate account for 14% of the GHE and CO2 by itself accounts for the other 86%. This can also be compared to the number of CO2 doublings that take place from 1 ppm to 390 ppm. That is roughly 8.6 CO2 doublings (1,2,4,8,16,32,64,128,256,390 ppm). Using 8.6 doublings from 1 ppm gives 25.8 °C. So their model is coherent, but saying that CO2 causes 86% of the GHE is extremely incorrect.
    To say that CO2 ‘doubled’ when it went from 1ppm to 2ppm is a fine demonstration of his complete ignorance on the subject. When scientists refer to a doubling of CO2, they mean from the pre-industrial (ca. 1750) value of 280ppm to 560ppm (which, if we keep going the way we are now regarding the use of fossil fuels, will happen sometime around 2050). Anything below that value of 280ppm is essentially meaningless to us going forward. In fact, if you look at the CO2 levels derived from Vostok ice cores, the CO2 level has never been below 180ppm for the past 400,000 years, even during ice ages.
    As Ammonite alludes to above, Tim Folkerts was spot on in his post that explains why you can’t consider CO2 in isolation. It (currently) contributes less than 20% to the greenhouse effect, but it is a very important effect in that it is one that mankind is primarily causing. And mankind is causing it because those ice core samples show that CO2 levels have never been above 280ppm for the past 400,000 years. A value of 390ppm is *unprecedented* in Earth’s recent history.
    The extra warming caused by the additional CO2 allows the atmosphere to hold more water vapour, which leads to even more warming, etc. Then when (not if, but when) large areas of the permafrost start to melt as a result, this will release trapped methane into the atmosphere. And methane is an even more potent GHG than CO2 :-\

  93. As Ammonite alludes to above, Tim Folkerts was spot on in his post that explains why you can’t consider CO2 in isolation. It (currently) contributes less than 20% to the greenhouse effect, but it is a very important effect in that it is one that mankind is primarily causing.
    False.
    Mankind’s CO2 emissions are only a small part of the total CO2. Completely stopping all increases will NOT change the world’s temperatures, but will directly and immediately harm many billions of innocents. Temperature change effect of trying to keep CO2 emissions at today’s levels? Less than 1/10 of one degree.
    The past three year’s global recession is directly traceable to the democrat’s and liberal’s CO2 programs and energy policies.
    No global model can work without assuming the massive multiplier effect of water vapor.
    No global model can work without assuming – with no basis in measured global values! – a sulfur particle/aerosol limit between 1960 and 1980 to sunlight.
    No global model has predicted the past 15 years of static temperature while CO2 has risen steadily.
    No global model can account for the 60 year short term climate cycle.
    No global model can account for the 800 year long-term cycle of the Roman Warming period, the Dark Ages, the Medieval Warming period, and the little Ice Age.
    No global warming model is, therefore, correct in predicting anything about the year 2050, 2100, or 2150.

  94. wayne says:
    October 25, 2010 at 1:01 pm
    “I am curious where you got the 4ºC average temperature for the oceans.”
    I didn’t get it from here:
    http://chalk.richmond.edu/education/projects/webunits/biomes/oclimate.html
    but its calculation of 3.8C awfully close to my estimated 4C. Mine was just a back of the envelope calculation. Not sure where I got my starting numbers but I think it was here:
    http://www.windows2universe.org/earth/Water/temp.html
    90% of the water in the global ocean is below the thermocline and the temperature is a pretty consistent 3C. For the surface layer I used 16C and solved for the average ((9*3C)+16C)/10 = 4.3C and rounded down to 4C which I figured should be accurate enough since 16C is on the high side for the portion of the global ocean above the thermocline as it’s the average temperature at the air/water interface and declines from there as you go deeper.

  95. “Jeff L says: October 25, 2010 at 11:56 am
    “I would love see a warmist post on here an analysis of why this is not a correct analysis.””
    If I have time, I would like to write one. I just doubt I will: this article is horrendously flawed, mainly because it confuses forcings and feedbacks and assumes linearity over a range where it is not justified e.g. the 3 C is because climate sensitivity is considered to be approximately linear pretty close to today’s temperature. This includes things like water vapour and cloud feedback.
    If the Earth were at -100 C, there would be negligible water vapour/cloud feedback and the climate sensitivity calculated there is completely irrelevant to today.
    By looking at total heating and dividing temperature by total heating, you confuse forcing and feedback. Without CO2, there would be effectively no atmospheric water vapour because by removing the CO2 you cause cooling. Water condenses out and Earth cools more – so the heating is actually a feedback to the CO2, not a separate radiative forcing.
    If you add excess water vapour, it condenses out within weeks and can’t sustain warmer temperatures so it doesn’t act as a forcing.

  96. Ian H says:
    October 25, 2010 at 2:33 pm
    “There is a problem in the argument here that should be pointed out. The forcing due to CO_2 cannot be exactly logarithmic, only approximately so in the region of concentrations not too different from now.”
    Quite right. John Tyndall demonstrated it experimentally 150 years ago. At very low concentrations longwave absorption increases in a linear fashion. Basically the first longwave absorption is like picking the low hanging fruit – it gets progressively more difficult to capture and due to the nature of absorption and re-emission you’ll never capture all of it as some portion of the energy at the far end of your absorption column will be re-emission at the primary absorption frequency.
    Everyone should really read the longwave absorption section on gases in Tyndal’s 1859 “Heat – A Mode of Motion” which is freely available in its entirety on books.google.com. Tyndal conducted thousands of experiments using different gases at different pressures with an ingenius experimental setup – for example he read the dial on his galvonometer using a telescope so that body heat didn’t muck up the energy being received by it. Another thing he did was use a second adjustable longwave energy source on the back-side of the galvonometer to keep the instrument its most sensitive linear range despite widely varying inputs on the front side of it. Just reading about his experimental setup with rock salt windows (rock salt, unlike glass, transmits longwave radiation with very little attenuation). It took a long time just to find a big enough monolithic rock salt crystal from which to cut and polish the column windows.

  97. Tim Folkerts says:
    October 25, 2010 at 2:05 pm
    “4 C would be the average temperature thru the whole depth of the ocean.”
    Correct.
    “The surface itself would still be around 15 C.”
    That depends on a whole bunch of factors. It’s 15C on average 15 thousand years into an interglacial period. During the peak of the glaciation cycle the surface is going to be largely ice with an average temperature well below freezing.
    “And that 15 C surface temperature is all that matters for IR radiation to the atmosphere. (Kinda like rocks deeper down are much hotter, but that doesn’t affect the IR radiation either.)”
    This is really really wrong. The ocean is fluid and although it mixes much slower than the atmosphere it does still mix through convection and it conducts reasonably well compared to rocks too. Rocks are nearly solid in comparison so you get no conduction and unlike water they are excellent insulators. There is no comparison in this regard between the earth’s crust and the global ocean.

  98. The last comment should read “rocks are nearly solid in comparison so you get no convection

  99. What happens if we use the period 1940 to 1970 to determine forcing and sensitivity?
    I thought so.

  100. George E. Smith says:
    October 25, 2010 at 3:46 pm
    “By the way, I wish people would stop assigning significant albedo contribution to snow and ice cover (mostly in te polar regions) rather than to cloud cover which averages about 61% on earth (cloud cover, not albedo)”
    Snow and ice cover is mostly near the poles, except for NH winter when it extends down quite a bit farther over the land surface. But that wasn’t my point. Interglacial periods during the last few millions years are roughly 1/10 the duration of the glacial periods. During the glacial periods snow and ice are not confined to near the poles. During that time a large fraction of the earth’s surface is covered year-round by glaciers and sea ice and there are very few clouds. At times in the earth’s history the coverage was 100% and these episodes are called “snowball earth”. Nobody quite knows what works to melt a snowball earth yet something does. My pet theory is that with most of the green plants gone and the ocean covered with ice there is no CO2 sink for the atmosphere so it remains constant. But underwater volcanoes keep right on chugging along belching CO2 into the ocean. Over the course of millions of years the pressure builds up under the ice like CO2 builds up in a bottle of homemade beer. If you put too much sugar in the bottle before you cap it the bottle will eventually explode. I think it might work like that with a snowball earth. Dissolved CO2 builds up in the ice-capped global ocean from volcanic emission until something, maybe an asteroid, comes along to break the seal then all of a sudden atmospheric CO2 level shoots up through the roof to 4000+ ppm and the greenhouse effect kicks into high gear melting the ice particularly near the equator. Green plants then recover quickly gluttonously feeding on the CO2 feast with little competition and lowering the albedo from snow level (85% reflectivity) to plant level (12% reflectivity) wherever they grow in a rapidly expanding range. And as sea ice melts that’s also a positive feedback as the ocean has single digit % reflectivity in most circumstances (high incidence angle and/or even a small amount of wave action).

  101. @George (con’t)
    There’s a big fundmental difference in the way clouds works as opposed to ice. Clouds form as the sunlight drives evaporation at the surface, convection makes it rise, adiabatic lapse rate makes it cool below the dewpoint. When the cloud forms it reflects 85% of the very energy source which creates clouds straight back out into space. So it has a really convenient negative feedback. If clouds as a net effect made the surface warmer, which would in turn evaporate even more water and make even more clouds, there’d be no such thing as clear sky!
    Snow and ice doesn’t have a negative feedback to stop any run-away effect of increasing cold. It has a positive feedback. The colder it gets at the surface the more snow and ice form. This is the dangerous side of potential climate change. For most of the last several million years Washington, D.C. was under a mile of ice. I don’t think we can pump enough CO2 into the atmosphere to stop that from happening again although one might understandably and fervently wish it were so. A repeat of the Eocene Climate Optimum would be nice – earth green from pole to pole, average temperature 6-8C higher than today, CO2 level 2000ppm and persisting in that general warm regime for hundreds of millions of years. That’s like a golden ages for the biosphere although taken in whole over the last 500 million years its the rule not the exception. Conditions like that are what laid down fossil fuels in the first place. In comparison we’re in a biologically deprived stunted freezing world perched on the brink of a 100,000 year long glacial epic. We should be trying to defeat the ice age not help it along.
    that limits how great the cloud cover can be for how long before it’s self-defeating. Snow and ice on the other hand have positive

  102. R. Craigen says:
    October 26, 2010 at 7:25 am
    “What happens if we use the period 1940 to 1970 to determine forcing and sensitivity?”
    Anthropogenic aerosols get blamed for temporarily overcoming the warming effect of CO2.
    If that’s true then the easy solution to global warming would then be to stop filtering the aerosols from our emissions. The worst consequence (other than global cooling) is acid rain as I recall and that was very regional nearest the biggest sources. All we’d have to do is carefully distribute sulfate emissions to avoid regional acid rains and there you go. It would also lower the cost of industrial processes and transportation (filtering costs $$$) so it would have a positive economic impact.
    I say go it for it. It’s plausible, fast acting, and worth a try since cost is less than nothing. I grew up in rural western New York 50 miles SSE from Bethlehem Steel which was supposed to be one of the worst places on earth for acid rain at the time and I didn’t notice a difference in any vegetation, wildlife, or agriculture after it largely shut down. The forest and farms and fields and river are all pretty much the same. Winters have been milder for sure which only lends more credence to the aerosol cooling hypothesis.
    http://en.wikipedia.org/wiki/Bethlehem_Steel

  103. *******
    Willis says:
    I decided to use the total Greenhouse Effect (as the ΔT) and then the energies involved. The total Greenhouse Effect is perhaps the least controversial aspect of the Global Warming debate. I will use the normally accepted value of the Greenhouse Effect as 30 °C.
    *******
    Willis, Dr Spencer says the total GHG effect is 60C, not 30C.
    http://www.drroyspencer.com/2010/09/why-33-deg-c-for-the-earths-greenhouse-effect-is-misleading/#comments
    This would make the fractional CO2 effect less (and more reasonable),but still too high IMO. Dr Spencer speculates that since water evaporation reduces the total GHG by about half, so increased evaporation reduces a given increase in forcing’s effect by 50%.

  104. Not being a real expert, i.e. I wasn’t around then to do real measurements, I suspect that not only the underwater volcanism played a role in the recovery to non-snowball status. Volcanos around the PacRim as well as across Europe and Africa wouldn’t have necessarily been idle. I wonder what the weight of the ice did to the stresses on the plate boundaries? I can imagine that there were some interesting tremors, if you were a seismologist.
    So much that we don’t know, or can’t know, but just try to deduce. Life is interesting if you’re really curious.

  105. George E. Smith says:
    October 25, 2010 at 3:46 pm
    “By the way, I wish people would stop assigning significant albedo contribution to snow and ice cover (mostly in te polar regions) rather than to cloud cover which averages about 61% on earth (cloud cover, not albedo)”
    —————————–
    One has to also factor in the optical depth of the clouds (the actual amount of sunlight reflected back out) which averages only 28%. It gets darker under a cloud but it does not become pitch black.
    So, clouds are only about 17 percentage points of the global Albedo of 29.8%. Land and Ocean Albedo is about 14 percentage points. During the ice ages, Land and Ocean Albedo may increase to about 17 percentage points so it does take alot of glacier and sea ice to move this number. But every percentage point is 3.4 Watts/m2 so every percentage point has a big impact on the climate.

  106. Regarding Bill Illis says: October 26, 2010 at 10:00 am
    Thanks for the post, now a question. So about 72% of the energy continues through the cloud cover to reach the surface. How has its wave length been affected? Is any more of it long wave?
    Thanks

  107. racookpe1978 says:
    The past three year’s global recession is directly traceable to the democrat’s and liberal’s CO2 programs and energy policies.
    I thought we were trying to have a grown-up discussion here about the science. That doesn’t seem possible on this site.

  108. Regarding Tim Folkerts says:
    October 25, 2010 at 5:15 pm
    Ouote “I can’t see any way to escape the logic that more water vapor (and more GHG’s in general) should and do have a net affect of warming the planet.”
    Tim, if I am following this correctly it is the residence time of the full spectrum of TSI in the earth system that matters. Your statement sounds true to me in regard to the atmosphere, but twenty percent less energy goes into the oceans due to the increase in water vapor. The short term effect is to heat the atmosphere, the long term is to cool the oceans.

  109. I don’t have any dispute with your numbers Bill; different people give different values for Albedo (total) and I don’t think that is a big problem since I don’t think it can be measured with great precision anyway.
    And of course although “cloud cover” may be described as 61% or some other number; that doesn’t mean that all of that is highly reflective. I have now several hundred photos of cloud tops taken from 36,000 ft on a daylight round trip to Oahu; from which I expect to be able to extract some range of variation in cloud brightness; bearing in mind the pixel numbers will likely be gerrymandered by my camera “stupidity”.
    I think the answer to David’s question is that the sunlight will likely undergo some spectral selectivity in navigating through the cloud; but other than that is not significantly altered. However the portion of the sunlight that gets absorbed in water or ice crystals or water vapor in the cloud; will of course become thermalized and result in downward LWIR emission. But that should always be kept separate from albedo considerations which are always sunlight spectra, wiht as I said the possibility of some spectral selectivity.
    And although the net reflectance may be 28% some deeper clouds will have a considerably higher reflectance, and some a lot less. I was quite surprised by the range of visible brightness of different clouds, in virtually the same position and sunlight; based on cloud morphology.

  110. “”” Steve Metzler says:
    October 26, 2010 at 10:47 am
    racookpe1978 says:
    The past three year’s global recession is directly traceable to the democrat’s and liberal’s CO2 programs and energy policies.
    I thought we were trying to have a grown-up discussion here about the science. That doesn’t seem possible on this site. “””
    Try over at c-r for a real adult debate. It is so easy to just ignore posts; there’s so many to read. That’s why they have libraries; people like to read different books too.

  111. Tim, here is another look att he same comment:
    Much of CAGW theory is based on the “T” factor of energy in the atmosphere?
    I see it basically like a freeway. If the incoming traffic (TSI) is constant, but the speed of certain cars reduced (residence time increased) by the cops (GHG) the total traffic, (energy/ temperature) increases.
    In the above the atmosphere is the freeway, and the TSI is incoming traffic. GHG are the cops that slow down certain red sports cars, (LW radiation) thus increasing the energy or density of traffic on the freeway. However, our earth has more then just freeways. We have many side streets that reduce the speed (residence time of incoming radiation) of traffic more then anything on the freeways. (atmosphere),
    These slower streets are the land and Ocean, and what happens here effects the residence time (speed) of vehicles more then what happens on the freeways. A photon of SW radiation entering and penetrating the ocean slows down dramatically compared to the freeway of the atmosphere. So the total traffic flow (earths energy budget) depends on the time spent on all streets, not just the freeways, or atmosphere.
    If water vapor and clouds increases in the atmosphere, (more cops enter the freeways) less traffic enters the side streets, the oceans, and even though freeway traffic increases due to more freeway cops, side street traffic is more sparse (cooling) and TOTAL TIME in the traffic system is reduced even though the freeway traffic is temporarily increased.

  112. “””” Steve Metzler says:
    October 26, 2010 at 4:57 am
    The author doesn’t even understand the first thing about what a doubling of CO2 actually means. Tom Kehr says in the original post:
    So all other factors in the Earth’s climate account for 14% of the GHE and CO2 by itself accounts for the other 86%. This can also be compared to the number of CO2 doublings that take place from 1 ppm to 390 ppm. That is roughly 8.6 CO2 doublings (1,2,4,8,16,32,64,128,256,390 ppm). Using 8.6 doublings from 1 ppm gives 25.8 °C. So their model is coherent, but saying that CO2 causes 86% of the GHE is extremely incorrect.
    To say that CO2 ‘doubled’ when it went from 1ppm to 2ppm is a fine demonstration of his complete ignorance on the subject. When scientists refer to a doubling of CO2, they mean from the pre-industrial (ca. 1750) value of 280ppm to 560ppm (which, if we keep going the way we are now regarding the use of fossil fuels, will happen sometime around 2050). Anything below that value of 280ppm is essentially meaningless to us going forward. In fact, if you look at the CO2 levels derived from Vostok ice cores, the CO2 level has never been below 180ppm for the past 400,000 years, even during ice ages. “””””
    Well how about a little consistency. either the global mean surface Temperature is a linear function of the log of the CO2 abundance, or it isn’t. Climatism 101 says it is; and if we accept that, then John’s numbers are correct.
    Your post is the very first time I have ever seen anybody refer to Climate Sensitivity as the rise in mean global surface temperature for an increase in CO2 from 280 ppm to 560 ppm. It is almost universal to refer to the Temperature rise per doubling; and that specifies a log function; which isn’t some arbitrary non linearity.
    We get these weasel words about , for very low values the change is linear with CO2, and then it gets harder to absorb more so it becomes logarithmic. It may become non-linear; but not logarithmic. Phil adds that at even higher concentrations it goes as square root of CO2 (I hope I’m not misstating what Phil has said.). The point is that in order to establish or solidify any sort of cause and effect relationship it is mandatory to be able to home in on a plausible mathematical relationship; that is traceable to basic physical laws (eventually)

  113. Steve Metzler says:
    October 26, 2010 at 10:47 am (Edit)
    racookpe1978 says:
    The past three year’s global recession is directly traceable to the democrat’s and liberal’s CO2 programs and energy policies.
    I thought we were trying to have a grown-up discussion here about the science. That doesn’t seem possible on this site.

    The CAGW “science” is being (deliberately) used by the “scientists” to generate their power, their funding, their influence, and their recognition. It is being used for their “feel good” sense of “doing something for society/Gaia/the environment.
    The so-called CAGW “science” is being used by the liberal and extremist politicians for THEIR power, their control of the world’s power, its future, and its economy. Same for the universities and the national labs – the funding and the sense of power is overwhelming.
    Pelosi’s restructuring of the oil exploration rules, of the funding for EPA/NOAA/NASA/GISS/ERDC etc, of her control of the energy and gas committees, of the tax and environmental legislation that was passed between her and the liberal-controlled Senate in 2007 and 2008 – in the specific name of fighting CAGW and funding alternate energy schemes – led to the destruction of the automobile, airline, housing, farming, and travel industries because they depend heavily on energy prices. Manufacturing, shipping, and heavy development immediately followed those losses into shutdown mode, and the recession was off into its course. The financial problems of Sept and Oct 2008 – just before the election of 2008 – came FROM the previous problems in the core industries. Those problems in finance, housing, securities, and insurance came BECAUSE the foundations of the economy (energy and production) were destroyed in the name of CAGW tactics.
    “Science” ? The so-called CAGW “science” is being used just as it is intended to be used.

  114. JDN says:
    October 25, 2010 at 1:00 pm
    DesertYote says:
    October 25, 2010 at 12:01 pm
    richard telford says:
    October 25, 2010 at 7:51 am
    There was a similar post to this on WUWT a month or two back. Not surprisingly they share the same flaw.
    The greenhouse effect of 30C is for a planet with an albedo of 0.3. The earth would not be cooler by more than 30C if the atmosphere was not radiatively active because the albedo would increase because of increased snow and ice cover.
    #
    What does a state change discontinuity at boundary have to do with the anything?
    ————————
    @DesertYote: It’s the difference between walking on water and walking in water.
    @Telford: I assume that he meant “all things being equal”, as in equal albedo, the earth would be 30C colder. Since it’s an analysis of formulas, that seems reasonable. Is this going to be a problem for you?
    ###
    I said discontinuous state change at a boundary, as in domain boundary. Your analogy is for a discontinuity within the problem domain. Try again.

  115. MarkR says October 26, 2010 at 6:27 am

    “Jeff L says: October 25, 2010 at 11:56 am
    “I would love see a warmist post on here an analysis of why this is not a correct analysis.””
    If I have time, I would like to write one. I just doubt I will: this article is horrendously flawed, mainly because it confuses forcings and feedbacks and assumes linearity over a range where it is not justified e.g. the 3 C is because climate sensitivity is considered to be approximately linear pretty close to today’s temperature. This includes things like water vapour and cloud feedback.
    If the Earth were at -100 C, there would be negligible water vapour/cloud feedback and the climate sensitivity calculated there is completely irrelevant to today.
    By looking at total heating and dividing temperature by total heating, you confuse forcing and feedback. Without CO2, there would be effectively no atmospheric water vapour because by removing the CO2 you cause cooling. Water condenses out and Earth cools more – so the heating is actually a feedback to the CO2, not a separate radiative forcing.

    You must live in a different world than I do … in my world, when you heat water up with sunlight some of it evaporates …

  116. Dave, I don’t think we are disagreeing. I was trying the make the point that — if you want to know about the IR coming and going from the surface at any given time, the temp at the surface is all you need to know.
    Certain
    >> “The surface itself would still be around 15 C.”
    > That depends on a whole bunch of factors. It’s 15C on average 15 thousand years into an interglacial period. During the peak of the glaciation cycle the surface is going to be largely ice with an average temperature well below freezing.
    AGREED 🙂 And if a square meter of the ocean surface is 15 C at a specific time (or 13 C or 18 C) then that square meter will radiate IR like water at 15 C (or 13 C or 18 C). And then you could average the temperatures and get some sort of global average. I have no special expertise in that area, so I was just using 15 C that had been presented as a reasonable number for the sake of discussion.
    >>“And that 15 C surface temperature is all that matters for IR radiation to
    >> the atmosphere. (Kinda like rocks deeper down are much hotter, but that
    >>doesn’t affect the IR radiation either.)”
    > … There is no comparison in this regard between the earth’s crust
    > and the global ocean.
    The one comparison — the one I apparently did not make clearly — is that we don’t need to know ANYTHING about the deeper layers to know about the surface IR. As you said (and I said in a later post) the internal details are vastly different. But if the temperature and the material of a surface are known, IR characteristics are determined. No IR comes from 1000 ft down, so whether it is hotter at that depth (like the land) or colder (like the ocean) is immaterial to the surface IR.
    Hopefully I made my point more clearly now. 🙂

  117. George E. Smith says:
    Well how about a little consistency. either the global mean surface Temperature is a linear function of the log of the CO2 abundance, or it isn’t. Climatism 101 says it is; and if we accept that, then John’s numbers are correct.
    That’s exactly the problem. It isn’t. There are many factors that contribute to rising mean global surface temperature besides CO2. Among the most important just off the top of my head:
    1. Rising temps caused by CO2 allow the atmosphere to hold more water vapour. This is a greenhouse gas with more than double the effect of CO2. It is a feedback rather than a forcing, but it still results in rising temps beyond what CO2 alone is responsible for.
    2. Rising temps cause glaciers, snow, and arctic ice to melt, thus reducing the Earth’s albedo. Less reflected sunlight means more absorbed sunlight/IR. Temps go up.
    The GCMs take much more than CO2 into account. Trying to set up CO2 as the sole contributor to warming is setting up a straw man.
    Your post is the very first time I have ever seen anybody refer to Climate Sensitivity as the rise in mean global surface temperature for an increase in CO2 from 280 ppm to 560 ppm. It is almost universal to refer to the Temperature rise per doubling; and that specifies a log function; which isn’t some arbitrary non linearity.
    You misunderstood my post. I was correcting John Kehr’s egregious error in his understanding of what doubling meant. It refers to the doubling from *pre-industrial* CO2 levels. Thus the first doubling will occur sometime in the future. There are a lot of people, John Kehr included, who seemingly think that doubling has already occurred.
    How many times do the same facts need to be repeated to you people? Oh, I know, an *infinite* number of times. Because it is your ideology that will not let you accept any science that would cause you to change your lifestyle. This is no different to creationists who refuse to accept evolution because it conflicts with their religion.

  118. George E. Smith says:October 25, 2010 at 2:46 pm
    Earth to Tim ! This planet has almost no other external energy input besides solar spectrum electromagnetic radiation from the sun; sunlight. Any reduction in sunlight for time scales of climate significance must result in a cooler earth.

    I agree completely with your last sentence. But I don’t think that by itself negates what I was saying.
    More specifically — Any reduction in sunlight for time scales of climate significance must result in a cooler earth as a whole (including the surface, the oceans and the atmosphere). So if the sun dimmed for some reason, then the earth as a whole would cool until it was emitting the same IR back to space as total solar radiation it receives. If liquid water (in the form of clouds) reflects some of that light away, then the earth as a whole would have to cool. By water vapor absorbing solar energy is still “part of the earth”.
    “Ultimately, it is the total solar energy that EARTH ABSORBS that determnines its Temperature over climate times scales.=; and H2O ALWAYS reduces that.
    Specifically, H2O vapor reduces the solar energy the SURFACE of the earth absorbs. “The earth” as a whole is still absorbing that energy. The “optical surface for IR” (somewhere up in the atmosphere) must be at an appropriate temperature (around 280 K give or take a bit) to radiate back to space the energy absorbed from the sun (whether absorbed by water in the atmosphere or by the surface itself). The physical surface does not need to be this temperature (and indeed is measured to be much higher than the blackbody temperature due to inputs from a slightly cooler atmosphere and a much hotter sun).
    I think there are way to many issues involved to figure this out in a discussion of a blog about climate sensitivity. Perhaps some smaller group should chat off-line to come up with something we can agree on and make it a new blog here.

  119. “”””” Tim Folkerts says:
    October 26, 2010 at 12:55 pm
    George E. Smith says:October 25, 2010 at 2:46 pm
    Earth to Tim ! This planet has almost no other external energy input besides solar spectrum electromagnetic radiation from the sun; sunlight. Any reduction in sunlight for time scales of climate significance must result in a cooler earth.
    I agree completely with your last sentence. But I don’t think that by itself negates what I was saying. “””””
    Tim, Chasmod, is always chiding me for writing too fast; and he means too long. But it seems no matter how long I make a post; I still fail to communicate.
    Yes it is true that earth’s Temperature depends on how much energy the EARTH absorbs; it also depends on how much solar energy REACHES THE PLANETARY SURFACE; meaning where the atmosphere terminates.
    And as you point out solar energy that is intercepted in the atmosphere (mainly by H2O) isstill absorbed in what is a part of the earth.
    I thought I explained quite clearly that energy from whatever source that is deposited in the atmosphere (and likely raises itsa Temperature, subsequently results in ISOTROPIC LWIR thermal emission; and ONLY HALF of that reaches the surface to get absorbed by something else(mostly the ocean surface).
    The other half of that atmospheric radiation takes off for outer space; to get lost. Yes it is likely to be reabsorbed in the atmosphere (partly) and that will result in a further isotropic emission, only half of which will proceed downwards. The end result, is that energy; for example incoming solar energy that gets captured by the atmosphere and therefore does not reach the surface (as solar energy); ends up getting split about 50:50 and only half of it ends up at the surface where it becomes a part of the long term energy sink.; it is not stored for long periods in the atmosphere; so it is a total energy losing mechanism. Without the atmosphere it would all reach the surface and mostly get stored less a small surface albedo reflection loss.
    Anything in the atmosphere which is capable by any mechanism of absorbing some part of the incoming solar spectrum energy from the sun; must necessarily reduce the total amount of solar energy the earth captures over time; and that must result in a lower mean global Temperature.
    Now I’m not saying that the Temperature will decline linearly with the reduction in insolation. Corrective mechanisms like changes in cloud cover will likely alter the result; just as those same measures would adapt to a real change in the extra-terrestrial TSI.
    People can nit pick all they want about what else might go on; but none of that changes the bottom line that the earth must cool if the total energy captured from the sun goes down; which it will, with more H2O in the atmosphere in any and all phases.
    Well I just might make an exception for noctilucent clouds; maybe it is possible that they send solar spectrum energy earthwards, that wouldn’t happen without them. But then I don’t know that Noctilucent clouds actually glow as a result of being illuminated by the sun; rather than charged particle interactions for example. But I’ll just leave it as the exception that proves the rule. Good luck on explaining any global warming with noctilucent clouds.

  120. This all reminds me of some horrible experiment trying to determine the relationship between the number of pins in a cat and the volume of its screech.
    How many pins will it take to get a 92db screech on a standard cat etc. etc.
    Have you ever tried to hold down a cat and stick in a pin? Ask any vet with scars down their face how they got them! Likewise, the atmosphere is not some passive entity that just sits there and gets warm according to some theoretical “cat-screech” equation. Like the cat it will be running round the walls doing everything you can conceive, puffing up in clouds, pouring IR into the vast emptiness of space … all helped along by IR cooling gas!
    Yes somehow sensible people still seem to be able to sit and talk about the theoretical number of pins you can stick in a cat and the “cat-screech” sensitivity!

  121. “”” Steve Metzler says:
    October 26, 2010 at 12:41 pm
    George E. Smith says:
    Well how about a little consistency. either the global mean surface Temperature is a linear function of the log of the CO2 abundance, or it isn’t. Climatism 101 says it is; and if we accept that, then John’s numbers are correct.
    That’s exactly the problem. It isn’t. There are many factors that contribute to rising mean global surface temperature besides CO2. Among the most important just off the top of my head:
    1. Rising temps caused by CO2 allow the atmosphere to hold more water vapour. This is a greenhouse gas with more than double the effect of CO2. It is a feedback rather than a forcing, but it still results in rising temps beyond what CO2 alone is responsible for. “”””
    Steve; you say:- “” 1. Rising temps caused by CO2 allow the atmosphere to hold more water vapour. “””
    Let’s add:- “” 2. Rising temps caused by H2O allow the atmosphere to hold more water vapour. “””
    and :- “” 3. Rising temps caused by CO2 allow the ocean to outgas more CO2. “””
    and :- “” 4. Rising temps caused by H2O allow the ocean to outgas more CO2. “””
    and:- “” 5. Rising temps caused by CO2 allow the ocean to “outgas” more water vapour. “””
    and:- “” 6. Rising temps caused by H2O allow the ocean to “outgas” more water vapour. “””
    and:- “” 7. Rising temps caused by sunlight allow the atmosphere to hold more water vapor “”””
    and:- “” 8. Rising temps caused by sunlight allow the ocean to outgas more CO2 . “””
    and:- “” 9. Rising temps caused by sunlight allow the ocean to “outgas” more water vapour. “””
    Now there is a portrait of absolute symmetry.
    Rising Temperatures; whether caused by sunlight, CO2 or H2O, allow the atmopshere to hold more water vapor; allow the ocean to outgas more CO2 (or take up less), and allow the ocean to outgas (evaporate) more water vapor.
    So now where is the hidden label that says CO2 is a GHG but H2O isn’t. why isn’t the sun a GHG sicne it warms the atmosphere and th4e ocean just like other GHGs do.
    And H2O of course is a feedback since it more CO2 causes more H2O; but more H2O also causes more CO2 so therefore CO2 is also a feedback; and more CO2 or more H2O causes more atmospheric and surface warming by sunlight so therefore sunlight too must be a feedback and not a GHG.
    I suggest Steve, that the Emperor has no clothes; and there simply is no basis for quite arbitrarily labelling CO2 as a GHG and NOT a feedback; whereas H2O is a feedback and NOT a GHG and sunlight is neither a GHG nor a feedback. when ALL of them are warming various things.
    And I am quite tired of that lame excuse that CO2 resides in the atmosphere for hundreds or thousands of years but H2O does not.
    WHEN, was the last time that earth’s atmosphere was observed to be devoid of H2O; that sometime temporary visitor to our atmosphere ??

  122. George E. Smith,
    You can’t find any legitimate problems with the science, so instead you play with words. Have at it.

  123. Sorry, I didn’t have time to read the article in enough detail. Silly question, but what do we mean by greenhouse effect? I’m assuming it’s the radiative effect, is that really contributing about 30degreesC? The reason I ask is because what about the fact that the oceans and atmosphere (and rotation of the planet so it is not always heating the same hemisphere) are transferring heat around the planet by conduction and convection. Doesn’t that ‘warm’ the planet, i.e. increase the average temperature because it reduces radiation loss from the surface because radiation is T to power 4, so the smaller the temperature range of the planet the less the total radiation loss for the same average temperature, or have I got my logic wrong?
    This is my reasoning – I’ve probably got this all wrong, but I’m imagining 2 bodies in space heated by radiation from a star. One body has poor conduction of heat from the hot sunny side to the cold dark side, for simplicity I’ll assume the hot side is all one temperature, let’s say 4 units (where 0 units = absolute zero) so the heat lost from that side is proportional to temperature to power 4 or 4x4x4x4 = 256. The cold side has a temperature of 2 units, so is losing 2x2x2x2 = 16. Add the two sides together gives a grand total of 272 radiation loss and the average temperature is (4+2)/2 = 3. The other object has perfect heat transfer (or is spinning so fast) so both sides are the same temperature, if this temperature is 3.415 then each side is radiating 3.415 to power 4 = 136, so the total for both sides is 272 with an average temperature of 3.145, in other words, quite a lot warmer on average than the object with poor heat transfer.
    So if I use the same simple logic to compare Earth and Moon, taking into account the differing albedos I come up with this (non radiative) heat transfer effect accounting for a large proportion (or may be almost all) of the difference in temperature of Earth and Moon. Mine was only an extremely simple calculation with finger in the air temperatures, really I guess it needs more accurate temperatures and to be integrated over a realistic set of temperatures over the entire surface at a typical point in time.
    Am I missing something, doing it wrong or were my finger in the air temperatures too way off the mark?

  124. “”””” MarkR says:
    October 26, 2010 at 4:05 pm “””
    Well Lacis et al have a problem if what they say will happen is true.
    With little or no water in the atmosphere; there won’t be much in the way of clouds; and the earth albedo will be very much lower; and you will have the mother of all warming forcings from a near TSI level of 1366 W/m^2, instead of about 1000.
    If you figure out the BB equilibrium Temperature it is no longer 255 K byt more like 276 K which is above zero.
    So their model simply doesn’t work; and you don’t need any taxpayer financed supercomputers to figure that out’ a stick on a sandy beach will do.

  125. Who’s playing with words ? I simply pointed out that the SCIENCE says that each of those things produces the same SCIENTIFIC results; so there isn’t any SCIENTIFIC basis for characterizing CO2 and H2O as different in their effects.
    Both exhibit the characteristics of GHG forcings which is pure SCIENCE; and both cause “regenerative” sort of effects; which the climatists call FEEDBACK which is SCIENCE; so in no qualitative way are they different to where one can be called a GHG forcing, and the other a non-GHG feedback. It’s a quite arbitrary and UNSCIENTIFIC dsitinction.
    But the climatists cchoose the most perjorative interpretation to make their unfounded case that H2O is not the most important GHG; which it clearly is.
    Over the last 600 million years; CO2 has been all over the map; yet for hundreds of millions of years, that had absolutely no recorded influence on the Temperature which simply refused to budge. And that is from the peer reviewed Science; not any wordmanship from me.

  126. Regarding : Tim Folkerts says:
    October 26, 2010 at 11:46 am
    “Dave, I don’t think we are disagreeing. I was trying the make the point that — if you want to know about the IR coming and going from the surface at any given time, the temp at the surface is all you need to know.”
    Thanks Tim, a couple of thoughts: I was responding to this, ““I can’t see any way to escape the logic that more water vapor (and more GHG’s in general) should and do have a net affect of warming the planet.” My response was that the atmosphere could well be heating up, but the oceans could well be cooling during this same period, and increased atmosphere heating, leading to increased water vapor and clouds, could reduce the flow of energy into the oceans where the residence time of energy in the planetary budget is far longer then in the atmosphere. The net affect of water vapor could well be cooling or even Newtonia, “for every action there is an equall and opposite reaction” (-; just on different time scales.
    As for this : “if you want to know about the IR coming and going from the surface at any given time, the temp at the surface is all you need to know.” I have several concerns. First it is not easy to KNOW the temperature at the surface and with out knowing the relative average humidity, even if the temperature was known within say .10 F, then one really knows little. Secondly of course one must know how much of the IR surface temperature is coming from above, it spectral band in detail, and how much is coming from below, the land and oceans, as both create the IR surface temperature. I do not see how just knowing it (a certain amount of IR radiation) is there, tells us it flow direction and residence time in the atmosphere or near and below the surface on 70% of the planet. My point is if the atmosphere heats up (due to increased water vapor) at the cost of reduced energy flow into the oceans where the residence time is far longer, the net long term result may be cooling, not warming. I hope I have expressed my self well.

  127. [SNIP – violation of site policy – wtf@fu.com is not a valid email address. the fu.com domain is in Arlington, VA and your comment originates at The University of Reading, UK., until you use a valid email address, all of your comments will be discarded – Anthony]

  128. George E. Smith says:
    But the climatists cchoose the most perjorative interpretation to make their unfounded case that H2O is not the most important GHG; which it clearly is.
    Please learn to read for comprehension. I’ve said up-thread several times that water vapour has more than twice the greenhouse effect of CO2. It’s hard to be logically consistent when you’re lying to yourself all the time, isn’t it?

  129. Here is a different way to estimate atmospheric sensitivity based on Miskolczi’s 2007 paper.
    http://met.hu/doc/idojaras/vol111001_01.pdf
    Miskolczi gives the ratio of St (flux transmitted through the atmosphere, directly to space) to Su (upward flux emitted at the surface) as 1/6, which is adopted in the following.
    The problem is to calculate the surface temperature of the earth including greenhouse effect but excluding all other effects such as evapotranspiration, convection, meridional atmospheric circulation, solar variation, etc. Based on Miskolczi’s St/Su ratio of 1/6, we take the no-atmosphere surface temperature of -18 degrees C and adjust it for the change of St/Su from 1 (no atmosphere) to 1/6 (greenhouse atmosphere). The calculation in Excelese is:
    T = (0.7 * 1365/(1/6 * 4 * 5.67E-8))^0.25 = 399 ºK = 126 ºC
    Where:
    0.7 = 1 – surface albedo of 0.3
    1/6 = St/Su ratio (Miskolczi 2007)
    St = upward radiation power transmitted directly to space (“window radiation”) W/m^2
    Su = upward radiation power at the surface W/m^2
    1365 = incoming SW radiation power W/m^2
    4 = ratio sphere surface to disk surface
    5.67E-8 Stephan-Boltzmann constant, J/(sec*m^2*K^4) or W/(m^2*K^4)
    0.25 = Stephan-Boltzmann exponent ^ -1
    For the no-atmosphere case (substitute 1 for 6), T = -18 deg C which is the commonly accepted value.
    The sensitivity based on this is
    labmda = (126-(-18)) / (0.7 * 1365 * 5 / 4)) = 0.121 ºC/(W/m^2)
    Where:
    5 = reflects the excess of window flux, greenhouse atmosphere over window flux, no-atmosphere (= 6 – 1).
    Sherwood Idso made several estimates of sensitivity
    http://www.warwickhughes.com/papers/idso98.htm#e4
    His best estimate based on the 8 cases he looked at is 0.100 ºC/(W/m^2)
    This exercise tends to confirm the thesis of this posting and Idso’s work, which together with this calculation gives a value of about 0.100 ºC/(W/m^2).

  130. George E. Smith says: October 26, 2010 at 2:07 pm
    Anything in the atmosphere which is capable by any mechanism of absorbing some part of the incoming solar spectrum energy from the sun; must necessarily reduce the total amount of solar energy the earth captures over time; and that must result in a lower mean global Temperature.

    OK — I will agree with that, but that is only half the equation. Since I agreed with you, I think you will have to agree with this:
    “Anything in the atmosphere which is capable by any mechanism of absorbing some part of the OUTGOING RADIANT ENERGY from the EARTH; must necessarily reduce the total amount of OUTGOING RADIANT ENERGY the earth LOSES over time; and that must result in a HIGHER mean global Temperature.
    If blocking incoming energy cools the earth, then blocking outgoing energy must warm the earth.
    So then the question becomes “is water vapor better at blocking incoming solar radiation, or is it better at blocking outgoing terrestrial radiation?” Does this result in a net warming or a net cooling effect?
    P.S. I’m not sure that “blocking energy” is really the best frame for discussing the issue, but even using this approach, the greenhouse effect shows up clearly.

  131. Tim Folkerts;
    So then the question becomes “is water vapor better at blocking incoming solar radiation, or is it better at blocking outgoing terrestrial radiation?”>>
    Neither the water molecules nor the photons care much about direction, so it isn’t better or worse at one than the other. HOWEVER, the path of a given photon may take it past more water molecules and hence have a higher percent chance of absorption and re-emission. This is where the concept of averages falls apart. You can’t assign 364 w/m2 to the whole planet and call it a wash. A photon emitted at the equator is going to plonck straight into a band of water vapour measured in tens of thousands of ppm. Emitted at the south pole at -90 degrees, there’s not too much water vapour in the air so the percent chance of being intercepted is lower. BUT, there’s way more photons emitted at surface at the equator than there are at the south pole. It isn’t a straight forward better or worse.

  132. “So then the question becomes “is water vapor better at blocking incoming solar radiation, or is it better at blocking outgoing terrestrial radiation?” Does this result in a net warming or a net cooling effect?”
    That is only part of the question. The “blocked” incoming solar radiation also increases the energy in the atmosphere. The question perhaps better asked is ” How is the residence time of all incoming TSI affected by changes in various GHGs?

  133. Well one of our climate scientists Bill Kinimonth has been saying for some time now that doubling CO2 will cause about 0.3 degree centigrade change (not 3 degrees cent.). See:

    So you have someone else with qualifications in agreement with your conclusions!.

  134. davidmhoffer says: October 26, 2010 at 7:10 pm
    >Tim Folkerts;
    >So then the question becomes “is water vapor better at blocking incoming solar
    > radiation, or is it better at blocking outgoing terrestrial radiation?”>>
    Neither the water molecules nor the photons care much about direction, so it isn’t better or worse at one than the other.

    Ah! But the light itself is different. The incoming light from the sun has much of its energy in the form of visible light, which passes quite easily thru the vapor and down to the earth – maybe 20% of the energy is blocked. But the outgoing radiation is almost entirely IR. I don’t have the specific numbers handy, but water vapor certainly blocks over half of the outgoing radiation.
    So, in fact, water DOES block the energy differently in different directions.
    I DO agree that different amounts of water vapor in different areas, along with different amounts of incoming solar radiation, means that simple averages are not sufficient to quantitatively determine the actual balance. For that we would really have to look sq km by sq km and add up all the results.
    But then we would need a computer model! 😉

  135. Steve Metzler says:
    October 26, 2010 at 12:41 pm
    “1. Rising temps caused by CO2 allow the atmosphere to hold more water vapour. This is a greenhouse gas with more than double the effect of CO2. It is a feedback rather than a forcing, but it still results in rising temps beyond what CO2 alone is responsible for.”
    That’s utter nonsense and we wouldn’t be alive to talk about it if were true. Water doesn’t care what makes it warmer so more water vapor would spawn more water vapor in your thesis and we’d have a runaway greenhouse. Since the earth has never experienced a runaway greenhouse the positive feedback you describe simply and demonstrably does not exist.
    The flaw in your thinking is that water vapor is lighter than air. Warmer surface temperature certainly does cause more evaporation but that water vapor quickly rises by convection and as it rises the pressure drops and as the pressure drops it cools. When it cools enough it reaches the dewpoint and condenses into a cloud. This is junior high school physical science called the water cycle.
    The cloud of course with a top measured in kilometers above sea level then reflects about 85% of the sunlight hitting directly back out into space. Adding to this effect is that most of the remaining 15% that gets absorbed by the cloud is transformed from visible to infrared light still kilometers above ground level. The water vapor and other greenhouse gases between the cloud and the ground now serve to insulate the surface against the cloud adding to the cloud’s awesome power to cool the surface beneath it.
    Further, there’s a thing called latent heat of vaporization that is a powerful force in removing heat from the surface. It takes one BTU to heat one pound of water by one degree. It takes over 1000 BTUs to change one pound of water into one pound of water vapor at the same temperature. So all that latent heat of vaporization is carried up from the surface by convection and released kilometers from the surface when water vapor condenses to form a cloud.
    The bottom line is that any surface warming caused by CO2 does not cause even more warming through increased water vapor because the water cycle simply doesn’t work that way. The water cycle has a built-in inescapable negative feedback with regard to increased surface temperature. Write that down.

  136. @Steve Metzler
    October 26, 2010 at 12:41 pm
    While we’re on the subject of CO2 here’s some more inconvenient facts from physics.
    The surface warming effect of CO2 comes by way of it absorbing upwelling infrared radiation and re-emitting it in all directions with approximately half going back towards the surface. That surface is in fact over 70% the surface of a body of water. You can’t heat water with infrared radiation. Infrared radiation is completely absorbed by the first layer of water molecules at the surface. You can increase the evaporation rate of water with infrared light but you can’t heat it. So for most of the earth’s surface downwelling infrared radiation doesn’t do jack diddly squat to heat the surface – all it does is increases the evaporation rate. It simply speeds up the water cycle and since the water cycle is a self-limiting process with negative feedback there’s no surface warming. Any insulation effect of CO2 over water is defeated by an increase in heat transport (evaporation, convective rise, condensation) from the surface to kilometers above the surface where it can more easily escape to the cold void of space.
    CO2 over land is a different story as land surfaces readily absorb infrared radiation. There you have a real honest-to-God surface warming effect because of it. But since land surfaces are less than third of the entire surface there’s only a third of the warming from CO2 that might otherwise be expected. This handily explains why the IPCC’s dire warnings about global warming fell so far short of observed warming and why the warming that is observed is primarily in the northern hemisphere because the NH has more land surface than the southern hemisphere.
    I never expect anyone who drank the CAGW kool-aid to someone who lets facts get in the way of their beliefs but these sir are the facts and they are indisputable.

  137. Dave Springer says:
    1. Rising temps caused by CO2 allow the atmosphere to hold more water vapour. This is a greenhouse gas with more than double the effect of CO2. It is a feedback rather than a forcing, but it still results in rising temps beyond what CO2 alone is responsible for.”
    That’s utter nonsense and we wouldn’t be alive to talk about it if were true. Water doesn’t care what makes it warmer so more water vapor would spawn more water vapor in your thesis and we’d have a runaway greenhouse. Since the earth has never experienced a runaway greenhouse the positive feedback you describe simply and demonstrably does not exist.

    This is basic physics. I’m not going to sit here debating with utter fools who are willfully ignorant of basic physics. The ‘runaway greenhouse’ effect? Hahahahaha. That’s the oldest one in the AGW denial book. Why don’t you go do some reading about the real science behind climatology instead of sitting here in this ignorant echo chamber? Oh wait, I know. It’s because your masters tell you that the real science is ‘propaganda’.
    For you people, black can be white and white can be black. Anything will do as an argument so long as it ‘proves’ that nothing mankind can do could possibly have an effect on nature. And you actually sit there and try to patiently explain to me your little pet theory that has been debunked so many times that we’re sick of it.
    I should never have come here in the first place, and rest assured, I never will again. The amount of stoopid on display is absolutely mind-boggling.
    [I’m going to leave your words in place exactly they were written. Perhaps against my judgment as a mod – since they violate several posting guidelines – but they are, shall we say , “instructive” about attitudes and prejudices and flat-earth constructs. Robt]

  138. “Anything in the atmosphere which is capable by any mechanism of absorbing some part of the OUTGOING RADIANT ENERGY from the EARTH; must necessarily reduce the total amount of OUTGOING RADIANT ENERGY the earth LOSES over time; and that must result in a HIGHER mean global Temperature.”
    Sure, that isn’t how I’d describe it but still the end result is a higher equilibrium temperature somewhere but not necessarily near ground or sea level. On a water world you can’t ignore evaporation and convection. When water evaporates it cools the surface where it evaporated. Pretty much everyone knows that, right?
    The Sahara desert has a mean temperature of 86F while tropical rain forests have mean temperatures of 81F.
    You’d think with all that vapor in the rain forest it wouldn’t be cooler than a desert. Yet it is and still yet the CO2 content in the well mixed atmosphere is the same in both places.
    But wait it gets worse for the case that more water vapor, a strong greenhouse gas, automatically makes it hotter.
    The albedo of desert sand is 40% whereas that of a rainforest is 10%. The surface of the desert is absorbing 30% less energy from the sun than the rainforest yet the mean desert temperature is higher.
    So here’s a perfect moment to ask: What’s Up With That?
    The surface albedo of the desert is

  139. Steve Metzler says:
    October 27, 2010 at 6:39 am
    Ad hominen is all you have in response to me? So soon? I really must’ve hit a nerve there. Sorry about that. The truth hurts, don’t it?

  140. Tom Folkerts;
    So, in fact, water DOES block the energy differently in different directions.>>
    It most certainly does not. You are conflating two issues. Water vapour blocks a given frequency or wavelength exactly the same regardless of direction. Determining how much of a given wavelength is travelling in a given direction is another matter, and yes the mix of “downward” wavelengths is different than the mix of “upward” wavelengths. May seem like a subtle difference but it isn’t.

  141. Alex Heyworth says: October 26, 2010 at 12:06 am
    One point that really bugs me about virtually every paper, post and comment I have ever seen on climate sensitivity and/or the earth’s energy budget is that everyone assumes that these issues can be satisfactorily explored on the basis of a static model. It is assumed that day and night, variations in TOA insolation due to the earth’s elliptical orbit, seasonal changes due to the inclination of the earth’s axis , and variations in the energy budget due to geographical location ,can all be averaged out without any impact on the analysis. Nowhere have I ever seen any proof that this assumption is valid, or even a reasonable approximation.

    It isn’t valid, as shown by Kramm et al:
    http://hockeyschtick.blogspot.com/2010/10/another-paper-on-fallacy-of-greenhouse.html

  142. @Steve Metzler
    So now that I’ve either taught you or reminded you that deserts at tropical latitudes have a mean surface temperature 5F degrees warmer than tropical rain forests despite the fact that the surface of the rain forest is much darker than desert sand and absorbs 30% more energy from the sun let’s move on to the tropical ocean surface temperature. Oceans are almost black so they absorb nearly 100% of any insolation reaching the surface or 40% more than desert and 10% energy than a rain forest. Plus the humidity is consistently high so there’s lots of water vapor to work as a greenhouse gas.
    That should REALLY get the mean surface temperature cranked up, right?
    Wrong. The mean surface temperature of the tropical ocean is 68F and nearly constant year round.
    So how come when we look at all these places where the incoming energy at the top of the atmosphere is the same and the concentration of CO2 is the same the cooler surfaces are always the ones where there is more water vapor?
    I granted at the beginning that increased CO2 will raise land surface temperatures but the effect is primarily where there is a dearth of liquid and gaseous water. So you’ll see what little effect it has primarily in the northern hemisphere because there’s more land in the NH and more in higher northern latitudes than lower latitudes because that cool refreshing water cycle is less active the farther north you go due to falling temperatures.
    Instead of ad hominem as your sole response try explaining these observations according to natural law as you understand it. You can include the ad hominem if it makes you feel better just don’t skip the science.

  143. Did you not conveniently miss the negative feedback of the clouds (er, water vapor) that is busily reflecting additonal solar energy from the earth – before it ever
    (1) penetrates the atmosphere,
    (2) hits the earth/water/plants/concrete;
    (3) heats up the earth/water/plants/concrete – at different rates and by different amounts and in different ways
    (4) gets re-radiated from the earth/water/plants/concrete – at different rates and by different amounts and in different ways and at different wavelengths
    (5) sees that re-radiated energy penetrate the (same/more/different water-vapor-barriered) atmosphere back up into the troposphere to
    (6) supposedly see the radiation energy get re-absorbed by the CO2
    (7) before it can re-radiate again either up or down
    (8) to be either re-reflected by the greater/same/lesser amount of water vapor/clouds/CO2 that is present?
    So – The whole CAGW argument centers on the (false) assumption that “nothing else changes in the atmosphere from the-year-before-nasty-humans-added-CO2-soot-aerosols” to “the next 50/100/1000 years if humans keep adding the same amoiunts )or more!) nasty stuff into the atmosphere.”
    But clouds? No – They are assumed the same. Past temperature changes of equal magnitudes to today’s changes? Ignored. Records changes and erased. Historical and written records changed to make the climate models simplistic assumptions come out right.
    But the models fail at the 5 year point. The 10 point. The 15 year point. They cannot even make the last 30 years come out right except by artificially introducing aerosols – with no measured worldwide data to account for the modeled finagle factor needed.
    But on this “model” we place a 1.3 trillion dollar tax debt.

  144. Dave:
    That should REALLY get the mean surface temperature cranked up, right?
    Wrong. The mean surface temperature of the tropical ocean is 68F and nearly constant year round.
    So how come when we look at all these places where the incoming energy at the top of the atmosphere is the same and the concentration of CO2 is the same the cooler surfaces are always the ones where there is more water vapor?

    It is ironic (and a telling proof of your question!) that the hottest/driest/least worthy and most worthless place on the earth – the Gobi Desert and Sahara Deserts are also the places with the highest CO2 levels, and least water vapor, least plant life, and least arable soil?

  145. Dave Springer says: October 27, 2010 at 5:59 am
    You can’t heat water with infrared radiation. Infrared radiation is completely absorbed by the first layer of water molecules at the surface. You can increase the evaporation rate of water with infrared light but you can’t heat it.

    Interesting — I had never thought about that. And after thinking about it, I’ll even go so far as to say IR almost always COOLS the oceans. (But that is only a part of the story!)
    Since the air cools off as you go higher in elevation, the oceans would be warmer (on average) than the air above them. Hence the top layer would generally be COOLING due to more IR heading out from the warm water than heading in from the cool air. This would make the very top layer COOLER than the layers below — very rarely warmer. (And sources I saw suggest this layer is on the order of 10^-5 m –> very thin, but not “one molecule thick.)
    The IR is slowly COOLING the oceans. But then there is the visible light. It can as does penetrate several meters into the oceans. It is heating this layer several meters thick, which (when combined with the IR) could indeed warm the oceans.

  146. More food for thought.
    http://oceanworld.tamu.edu/resources/oceanography-book/oceansandclimate.htm

    Influence of Greenhouse Gases Especially Water Vapor
    Let’s look at how greenhouse gases influence the climate system, and how they might cause climate change. The ideas below come from George Philander’s book, Our Affair With El Niño, chapter 7: Constructing a Model of Earth’s Climate, page 105.
    1. Earth with no atmosphere
    If earth had no atmosphere, if it had a land surface that reflected some sunlight like the real earth, and if it were in equilibrium with solar heating, the average surface temperature of earth would be -18°C (0°F), far colder than the average temperature of our earth, which is 15°C (59°F). Worse, the surface would cool down to around -160°C (-250°F) soon after the sun set because the surface would radiate heat to space very quickly, just as the moon’s surface cools rapidly as soon as the sun sets on the moon.
    2. Earth with a static atmosphere and no ocean
    If the earth had a static atmosphere with the same gases it has now, but with little water vapor and no ocean, the average surface temperature of earth would be 67°C (153°F). This is much warmer than our earth. The planet would be so hot because greenhouse gases in the atmosphere help keep heat near the surface, and because there is no convection, and no transport of heat by winds. Adding winds cools the planet a little, but not enough.
    3. Earth with an atmosphere and ocean
    Earth has an atmosphere and ocean, and the average surface temperature is a comfortable 15°C (59°F). Water evaporates from the ocean and land, cooling the surface. Winds carry the water vapor to other latitudes, and sometimes high up into the air, where heat is released when the vapor condenses to water.

    There’s your feedback effect from water vapor. It cools the average surface temperature of the planet by an incredible 100 degrees F according to George Philander who holds a PhD in Atmospheric and Ocean Sciences from Harvard and is a full professor of same at Princeton. Philander was the director and/or chairman of Geoscience and Atmospheric and Oceanic Science at Princeton from 1990-2006.

  147. @Steve Metzler
    So to sum up the effect of CO2 on the earth’s surface temperature it:
    1) initially raises the average temperature from below freezing to above freezing
    2) at that point it activates the water cycle
    3) the water cycle takes over from greenhouse gases and puts a cap on global average temperature via strong negative feedback to increasing temperatures
    The only thing we have to fear is a tipping point where the average temperature of the planet falls below freezing pretty much ending the water cycle and raising the albedo of the planet from near 10% to over 80% which is equivalent to the sun becoming 70% dimmer.
    And you, evidently, want to get us closer to that tipping point instead of farther away from it. Incredible. Just f’ing incredible.

  148. racookpe1978 says:
    October 27, 2010 at 11:23 am

    Did you not conveniently miss the negative feedback of the clouds (er, water vapor) that is busily reflecting additonal solar energy from the earth – before it ever
    (1) penetrates the atmosphere,

    Yes, indeed I did and it was purposeful. My pedagogic style is to leave some deductions up to the student as a means of helping me judge how well he understands the underlying principles and ability to carry them out to the proper conclusions. The tropical rain forest, at an altitude of a kilometer or more above the canopy has an average albedo higher than that of desert sand due to all the clouds. The canopy itself (the actual surface where we and most other terrestrial life lives and breathes) still has an albedo around 10% so my statement is still true but it wasn’t the whole truth. I left the rest of the truth as an exercise for the reader. You picked up on it pretty quick. Let’s hope Steverino does too.

  149. Tim Folkerts says:
    October 27, 2010 at 11:38 am
    I understand IR hitting a water surface creates convection in the top millimeter. Presumably that’s because the topmost layer of molecules is being removed by evaporation which cools the next layer of molecules down and then they sink a little bit and are replaced by slightly warmer molecules from below which are then carried off by evaporation and so on. I’m not sure if there’s any consensus on whether the effect is net cooling or warming of the water. The sign of the temperature change is probably dependent on relative humidity and winds. I looked and wasn’t able to find anything that stated that more than 20% of the downwelling IR energy could be absorbed in any circumstance. So it’s probably technically possible to heat water with infrared if you can keep the air above it perfectly still and saturated with water vapor. In the real world that is very rare and would require some sort of temperature inversion near the surface to prevent convection from carrying the water vapor upward just like the tropopause under most circumstances stops convection from proceeding into the stratosphere.

  150. Tim Folkerts says:
    October 27, 2010 at 4:54 am
    “…The incoming light from the sun has much of its energy in the form of visible light, which passes quite easily thru the vapor and down to the earth – maybe 20% of the energy is blocked. But the outgoing radiation is almost entirely IR. I don’t have the specific numbers handy, but water vapor certainly blocks over half of the outgoing radiation…”
    I trust you are aware that 54% of the sun’s radiation is in the infra-red (IR) region?
    This means that over half the incoming radiation must also be blocked by water vapour. It is also interesting to note that the atmosphere is densest at ground/ocean level and has the highest humidity here. Therefore, most of the outgoing IR is absorbed by the first yards of atmosphere above the surface. In addition, over 90% of absorbed photons are not re-emitted, rather due to collisions with other molecules they are converted into kinetic energy. The heat is then dissipated in the upper atmosphere and eventually out to space.
    Until climate scientists stop using computer models, and start to try and understand real world macro-physics, no insight about how our climate operates will be forthcoming. It’s a travesty that so much money has been spent to deliver so little!

  151. Just to make my position crystal clear…
    There’s not a doubt in my mind that more CO2 over arid land surfaces (arid due to either geography or high latitude) raises the average temperature by the no-feedback amount of around 1.1C per doubling beginning at a baseline of 200+ ppm. In more humid conditions and over water not so much if at all. Overall, it will increase the average temperature over the entire planet but the distribution of the temperature increase is not homogenous. It tends to warm up the frozen places first where it helps to bring the temperature above freezing and thus activate the water cycle which then puts a cap on further heating and it tends to leave the warm humid places unchanged.
    To verify this we can look back into the geologic column where we find that when the earth is warmer overall by just 6-8 degrees and CO2 concentration is upwards of 2000ppm it’s pretty much a green planet from pole to pole. Call me strange if you want but I tend to prefer green plants to barren rock and ice. The only reason a person wouldn’t want more CO2 in the atmosphere is either because they’re in love with rocks and ice (I call them “ice huggers”) and/or they don’t understand how the greenhouse effect works to set surface temperatures in conjunction with the water cycle on a world with an inclined axis and 70% covered by a global ocean an average of 4000 meters deep.
    Fear the cold. Embrace the warm. Fossil fuels – burn baby burn. Use it before you lose it. I doubt we can prevent the near term end of the Holocene interglacial with the puny amount of CO2 we can pump into the air by burning fossil fuels but one thing is for damn sure – we’ll hasten the end by pumping less of it into the atmosphere.

  152. “”””” Tenuc says:
    October 27, 2010 at 1:12 pm
    Tim Folkerts says:
    October 27, 2010 at 4:54 am
    “…The incoming light from the sun has much of its energy in the form of visible light, which passes quite easily thru the vapor and down to the earth – maybe 20% of the energy is blocked. But the outgoing radiation is almost entirely IR. I don’t have the specific numbers handy, but water vapor certainly blocks over half of the outgoing radiation…”
    I trust you are aware that 54% of the sun’s radiation is in the infra-red (IR) region? “””
    Well actually not really. A text book plot of the actual solar spectrum places the peak spectral irradiance at about 480 nm which puts the visible IR boundary of 800 nm at 1.67 times the peak wavelength. Standard Black Body radiation curves, suggest that only 40% of the total is at longer wavelengths than that. But a detailed table of actual TSI spectrum values says that 56.023% of the total is at SHORTER than 800; which means only 44% is in the IR.
    That is not an inconsequential difference from 54%.
    These numbers are from 20th century research; so I dare say that a 2010 review would change some of the numbers a bit; but climatists are busy trying to determine the correct R^2 value to use for their statistical research results; so they are not really interested in real physical data gathering.
    It is interesting to contemplate the enormity of the supercomputer computations that Lacis et all had to go through to show that CO2 is the big control knob.
    He said that the GHG (and presumably non GHG feedback gases like H2O) have absorption spectra containing “thousands” of absorption lines; each of which has to be individually calculated.
    So for some arbitrary location somewhere in the atmosphere, and at some earth location at some epoch of time; you have to determine from the model what the local Temperature and Density are; and the species living there, then for each of the thousands of spectral lines you have to determine the Doppler and pressure line broadening for those circumstances; and integrate the total energy that will be absorbed from whatever EM radiation flux is passing through that sample; and you do that for each of the thousnds of lines; and then you compute the local temperature change that will result from that temperature change, and the resulting atmospheric thermal radiation that occurs, and then you have to move on to the next atmospheric layer; both up and down to compute the changes in the temperature, and pressure, and then recalculate all the line broadenings and new absorption spectrum appropriate for those conditions; and then after you are finished with the analysis for that location from the surface to outer space, you then have to go to the next spatial location and repeat the whole process, until you have a properly Nyquist sampled set of spatial data ; and then you have to repeat the whole process for the neaxt time epoch to see how it all changed ; and perhaps keep doing that until you have properly Nyquist sampled perhaps a whole year of sun orbiting changes; and meanwhile you have to deduce what phase changes will take place for non-GHG feedback mechanisms like H2O vapor and clouds; and then when finally you have figured out what the mean global surface Tempertaure is for all of this data set; you have to go and do it all over again but now with twice as much CO2, so you can compute how much the Temperature changes for the CO2 doubling; to arrive at a final value for Climate Sensitivity.
    I knew there was a reason, that I didn’t go into the climatism field; it just seems like too much hard work; and I can see why you have to revamp your results from time to time; when people say you aren’t doing it properly.
    But since I spent so much of my hard earned dollars in taxes to buy a supercomputer for Drs Lacis, and Schmidt it is good that they have done this pioneering work for us; so that we don’t have to.
    But I still have a lot of confidence in my stick on a sandy beach; and I keep coming to the same conclusion:-
    HEY !! IT’S THE WATER !!

  153. I noted somewhere above that near surface temperature inversions potentially stop convection enough to allow downwelling IR energy from CO2 to not quickly rise back up from a wet surface in the form of latent heat of vaporization. I said those should be rare very near to the surface.
    Turns out they’re not that rare. Fog is the result of near-surface temperature inversion. Most of us have seen it before and a few of us see it more than they’d like but it’s still can’t be called common in most places at most times. Fog is cooler than the air above it which stops it from rising and brings the vaporization rate below it to essentially zero.
    Inversions farther up from the surface, if they persist, end up spawning violent weather when they’re eventually penetrated as all the pent up convective energy is released around the point of penetration (thunderstorms and hurricanes). There was a recent graphic on WUWT showing the track of colder water in the Atlantic underneath the path of the larger hurricanes so I think it’s safe to say that these events end up cooling the surface too before they’re over.

  154. George E. Smith says:
    October 27, 2010 at 3:06 pm
    re; 44% of insolation in the IR range
    Keep in mind that’s almost all in the near IR spectrum where CO2 is transparent to it. CO2 is not a significant absorber of solar spectrum energy. Water vapor is opaque in the near IR however. Hardly any radiation from the sun is in the far IR where CO2 becomes opaque. The earth’s surface on the other hand radiates almost exclusively in the far IR with a couple of CO2’s sweet spots right near the peak power frequency. But it shares one of those sweet spots with water vapor so in the presence of water vapor CO2’s effectiveness is diminished to some extent.

  155. davidmhoffer replies to: “So, in fact, water DOES block the energy differently in different directions.”
    It most certainly does not. You are conflating two issues. Water vapour blocks a given frequency or wavelength exactly the same regardless of direction.

    I agree 100% that a given wavelength is blocked the same in either direction.
    the mix of “downward” wavelengths is different than the mix of “upward” wavelengths. May seem like a subtle difference but it isn’t.
    And that is exactly my point. See, for example, this earlier post for a handy diagram of the spectra of incoming radiation from the sun and outgoing radiation from the surface. http://wattsupwiththat.com/2010/05/06/hyperventilating-on-venus/
    Incoming radiant energy is ~25% absorbed; outgoing radiant energy is 85% absorbed. Most of this is due to water. How can you disagree with “water DOES block the energy differently in different directions.”

  156. George E. Smith says: October 27, 2010 at 3:06 pm
    A text book plot of the actual solar spectrum places the peak spectral irradiance at about 480 nm which puts the visible IR boundary of 800 nm at 1.67 times the peak wavelength.

    Except text books also put the visible/Ir boundary at 700 nm — perhaps as far as 750 nm, but I have never seen a source that puts it quite as far as 800 nm.
    Obviously this fuzzy boundary for IR means that the numbers will also be a bit fuzzy. (Of course, what we call it will not change how much is absorbed by H2O or CO2.)

  157. I’m a bit confused by your comments, Dave.
    I understand IR hitting a water surface creates convection in the top millimeter. Presumably that’s because the topmost layer of molecules is being removed by evaporation …
    I was actually making a point which I believe is the opposite of your conclusion. I say IR creates convection by COOLING the surface, not warming it!
    You considered the IR hitting the surface, but I never see you consider the IR LEAVING the water. The IR leaving must almost certainly be more than the IR arriving, since the ocean surface is almost certainly warmer than the average temp of the atmosphere above it that radiates down. The warmer water must then be radiating more IR up than the atmosphere is radiating down. So since net IR energy is leaving the water, the water must be cooling at the surface due to IR.
    The COOL water at the surface causes convection. (Warm water at the surface would cause very little convection, since the warm water would want to stay at the surface.)
    I looked and wasn’t able to find anything that stated that more than 20% of the downwelling IR energy could be absorbed in any circumstance.
    You explicitly claimed that “Infrared radiation is completely absorbed by the first layer of water molecules at the surface.” Unless I am missing something, your statement assumes (and I agree) that water is very close to a perfect black body for IR and hence absorbs 100% of the downwelling IR. (Although I still think that you need at least several thousand molecular layers to absorb the IR – not jsut a single layer.)
    Other issues you mention like wind and humidity certainly play additional roles in surface temperature, but the IR itself is cooling the surface!

  158. Tim Folkerts says:
    October 27, 2010 at 8:19 pm
    George E. Smith says: October 27, 2010 at 3:06 pm
    “Obviously this fuzzy boundary for IR means that the numbers will also be a bit fuzzy. (Of course, what we call it will not change how much is absorbed by H2O or CO2.)”
    The fuzzy boundary is because the boundary is an arbitrary point set by the frequency response range of the human eyeball. Some animals see farther into the near infrared than others. Rattlesnakes can see into the far infrared. Birds and bees can see into the ultraviolet. EMR is EMR. Wavelength primarily changes the way the wave propagates through matter. For instance a microwave will go through the ionosphere but radio waves can be reflected by it. Visible and infrared light won’t penetrate a sheet of paper but the paper is almost transparent for microwaves and radio waves and semi-transparent to x-rays. There’s no particular point where nature lays down a border saying “red stops here and becomes infrared”.

  159. “You explicitly claimed that “Infrared radiation is completely absorbed by the first layer of water molecules at the surface.” Unless I am missing something, your statement assumes (and I agree) that water is very close to a perfect black body for IR and hence absorbs 100% of the downwelling IR.”
    Yes but that doesn’t mean it does or does not raise the sensible temperature. Water and water vapor can co-exist at exactly the same temperature yet the vapor can carry a tremendously larger amount of absorbed energy as latent heat that will become sensible heat again when it condenses. Latent heat isn’t radiative. It’s transported mechanically.

  160. George E. Smith says:
    October 27, 2010 at 3:06 pm
    “A text book plot of the actual solar spectrum places the peak spectral irradiance at about 480 nm which puts the visible IR boundary of 800 nm at 1.67 times the peak wavelength. Standard Black Body radiation curves, suggest that only 40% of the total is at longer wavelengths than that. But a detailed table of actual TSI spectrum values says that 56.023% of the total is at SHORTER than 800; which means only 44% is in the IR.
    That is not an inconsequential difference from 54%.”

    The 54% came from “Power From The Sun” -2001 – William B. Stine and Michael Geyer
    Hi George, it looks like we could be falling foul of the definition of where the IR range begins. They peg IR as starting at 0.7 micrometers, while your text puts the boundary at 0.8 micrometers – enough to account for the discrepancy perhaps?

  161. “””” Tenuc says:
    October 28, 2010 at 7:30 am
    George E. Smith says:
    October 27, 2010 at 3:06 pm
    “A text book plot of the actual solar spectrum places the peak spectral irradiance at about 480 nm which puts the visible IR boundary of 800 nm at 1.67 times the peak wavelength. Standard Black Body radiation curves, suggest that only 40% of the total is at longer wavelengths than that. But a detailed table of actual TSI spectrum values says that 56.023% of the total is at SHORTER than 800; which means only 44% is in the IR.
    That is not an inconsequential difference from 54%.”
    The 54% came from “Power From The Sun” -2001 – William B. Stine and Michael Geyer
    Hi George, it looks like we could be falling foul of the definition of where the IR range begins. They peg IR as starting at 0.7 micrometers, while your text puts the boundary at 0.8 micrometers – enough to account for the discrepancy perhaps? “””
    Hi Tenuc,
    Well I am sure you are correct about the source of the discrepancy. It’s also not a point worth spending a lot of words on. I’m quite happy to use your number of 700 rather than 800.
    Lots of references to the entire EM spectrum, simply say that “light” (visible) is the single octave from 400 to 800 nm. I know I used those numbers in an Application Note on Photometry of LEDs in a 1972ish industry paper; and I recall making the statement that more information is communicated to humans in that single visible Octave than from the entire remaining 24 or 25 or so octaves of the generally observable EM spectrum. Just a brash statement for effect to say we see a hell of a lot with our eyes.
    But to get a bit more critical, I would go to “The Science of Color.” published by the Committee on Colorimetry of the Optical Society of America (to which I belong; society; not committee). They give an early 1924 CIE plot of the Photopic Eye Response (not low light Scotopic), which they plot from 380 to 700 nm. They also show a 1931 Chromaticity diagram (color triangle) that terminates at 700 nm.
    But that 700 nm Red is qute visible to at least young eyes; in fact it is very visible; and a table of standard Tri-stimulus values of the Spectrum (perimter of the chromaticity diagram) (monochromatic), which gives 1.0002 at 555nm for the peak ybar value drops to 0.0041 at 700 nm (and about the same at 420 nm). The red drops to 0.0001 ybar at 760 nm; and at my age I can’t see that; and they terminate the table at 780 with a nominal zero value.
    It so happens that the Standard wavelength we use for VCSEL laser diodes as used in Optical Laser mice is 780 nm; and none of us can see those. We use that wavelength because Silicon CMOS sensors are more efficent for 700-780 nm wavelenghts than for the 900 nm of real IR lasers.
    So pedantically 400nm is clearly visible, and 800 is clearly not visible and not much useful red is contained in the 700-780 range. So I’m not unhappy with a 700 nm cutoff, and your numbers so long as we cite that cutoff so we know where we get the numbers from. The boundary line is not too germane to the argument as to how solar spectrum energy is treated; only the numbers shift a little.
    George

  162. For Tim and Dave, Re water absorption.
    The IR Handbook gives some good data for seawater.
    Seawater is MOST absorptive at and around 3.0 Microns (solar spectrum; not thermal). The Absorption coefficient is about 9,000 cm^-1 which means attenuation to 1/e (37%) in about 1.1 microns; which would be 99% absorbed in 5.5 microns. It then drops considerably to as low as 200 cm^-1 at 4 microns; beyond which only 1% of sunlight remains, and reaches the second highest peak of maybe 2000cm^-2 at 6.3 microns, and then drops to about 900 at 700 microns from where it rises slowly to a final max of about 3200 cm^-1 at about 15-20 microns; right where the CO2 peak is and water’s best LWIR peak.
    From there is drops about linearly on a log log plot to maybe 300 cm^-1 at 100 microns. So 1000 would give a 1/e depth of 10 microns so 50 microns absorbs 99%.
    So definitely not a monomolecular layer by any stretch; but a very thin layer for the LWIR thermal spectral range. The linear log-log plot continues all the way out to 10 cm which is 3GHz, where the slope about doubles as water gets more transparent to radio-waves.
    I think for the bulk of the 5.0 to 80 micron surface or atmospheric thermal spectrum, 2,000 cm^-1 is good number which is a 5 micron 1/e depth or 25 micron 99% absorption depth (1 mil).
    That to me is a thin layer that can easily heat sufficiently to evaporate profusely.
    In contrast at the sunlight peak of around 470 nm , the absorption coefficient is 0.0001 cm^-1 which is a 100 metre 1/e depth, and 500 metres for 99%.
    Actually in a lot of sea waters; biologicals in the water; will cause more losses; but you get the idea that solar energy is deposited deep in the ocean; while the downwelling LWIR from the atmosphere is stopped in a mil of water.

  163. Dave Springer says: October 27, 2010 at 9:22 am
    The albedo of desert sand is 40% whereas that of a rainforest is 10%. The surface of the desert is absorbing 30% less energy from the sun than the rainforest yet the mean desert temperature is higher.
    So here’s a perfect moment to ask: What’s Up With That?

    My first suspicion would be that the cloud cover is the main difference.
    I checked into the Amazon basin and found a credible link that suggests that area has a 70% – 80% cloud cover (http://mclean.ch/climate/Cloud_Amazon.htm). I didn’t find a similar estimate for the Sahara, but I strongly suspect it is closer to 10% – 20%.
    * If 80% of the sunlight reaches the surface in the Sahara and 60% of that is absorbed, that results in 48% of the total that gets absorbed.
    * If 30% of sunlight reaches the surface of the rain forest and 90% of that is absorbed, that results in 27% of the total.
    These are of course rough numbers, but it clearly shows that rain forests could easily absorb less total solar energy (and hence be cooler on average).

  164. @Tim
    Yes sir. The water cycle (clouds are a part of it) is the big Kahuna when it comes to surface temperature on a water world. CO2’s only important role (other than plant food!) is keeping it warm enough for the water cycle to be active. Evidently we don’t have quite enough CO2 because warm spells like the Holocene interglacial only last about 15,000 years then there’s 100,000 years of glaciers and sea ice covering everything all year round from 40 to 90 degrees latitude. That’s been the cycle for the last several million years. I don’t think humans can possibly pump enough CO2 into the atmosphere by burning fossil fuels to break that cycle. At best maybe delay the inevitable by no more than a few centuries. That might be enough time to figure out and put in place some other artificial means of preventing the next glacial period.


  165. George E. Smith says: October 28, 2010 at 11:40 am
    The IR Handbook gives some good data for seawater….
    Thanks for the post. I had seen a similar graph and come to similar conclusions about penetration depths.
    The one conclusion I don’t completely agree with is “That to me is a thin layer that can easily heat sufficiently to evaporate profusely”
    It seems (and I could be wrong) and you and Dave are thinking that the ~300 W/m^2 of downwelling IR from the atmosphere is simply going to evaporate away the ocean surface without heating the deeper layers. But since there is also ~ 400 W/m^2 upwelling LWIR from the ocean; all the downwelling LWIR can really do is keep the surface from cooling too quickly. Of course, the solar IR also mostly affects the surface layer, so midday I would not be surprised to see net heating of this thin layer and enhanced evaporation.
    ———
    Perhaps the most important conclusion is that we do not have the data nor the time (nor the expertise, I suspect) to really answer these questions here. This blog is fantastic for learning about the various opinions and concerns about GW, but it is really not effective for learning about the science, and it is even less effective for coming to new conclusions.
    That is why people make careers out of tackling problems like this. That is why there is peer review of new ideas by others who have the knowledge to offer informed criticism. That is why people develop elaborate computer programs to take into account more and more of the variables we are musing about.
    As a friend once said — if it was so easy that you could figure it out the first time around, they wouldn’t call it “re-search”. 🙂

  166. MODERATOR:
    It looks like I missed the “” in the previous post after the second line:
    ” The IR Handbook gives some good data for seawater… ” 🙁

  167. Even weirder — my formatting comment to the moderator left out the symbols in the quotation marks! I missed the ending html italic tag, but even typing the symbols with spaces between them didn’t work. C’est la vie.

  168. @George
    Thanks for the IR optical depth data in seawater!
    I knew it was a very thin layer. Elsewhere I read the observed action all takes place in the first millimeter even though complete absorption takes place in just a few microns.
    Evaporation however is a surface event. In a boiling fluid (vaporization pressure equals environmental pressure) vaporization can occur anywhere. In evaporation where the vaporization pressure is only a fraction of environmental pressure it occurs in the top layer of molecules as they have less binding energy than molecules completely surrounded by other water molecules.
    In the real world there is going to be some other processes going on due to impurities in the water which are not subject to phase change. It’s unclear to me if there are any real world conditions where IR impinging on a water surface could possibly raise its sensible temperature. It would seem that at the least this would require non-moving saturated air at the interface like in a fog bank. All I know for sure is that when evaporation is occuring it is removing sensible heat from the surface and the vapor itself doesn’t have a higher temperature than the bulk liquid it leaves behind because the heat it carries away is latent which won’t have any heating effect on the surrounding environment until the vapor changes phase back to a liquid and that usually occurs at some significant altitude so the net effect is like an express elevator mechanically carrying heat away from the surface and dumping it thousands of feet higher up in the troposphere or maybe even in the stratosphere when a convective cell gets wound up really tight.

  169. @Tim
    “The one conclusion I don’t completely agree with is “That to me is a thin layer that can easily heat sufficiently to evaporate profusely””
    There seems to be some confusion here. No “heating” is required. Temperature is an average of the individual motion of an exceedingly large number of molecules. In all this motion a few molecules will be moving much faster than the bulk and a few moving much slower. The fastest moving molecules in the bulk are the ones ripe for a phase change to vapor with just a little extra nudge. When the phase change happens it’s like a rubber band snapping and all the potential energy in the stretched rubber gets packed into the vapor molecule as latent heat (potential energy not the energy of motion which a thermometer can sense). The unvaporized molecules at the other end of the broken rubber band suddenly lose a lot of energy of motion – about a thousand times as much energy of motion as is contained in the latent (potential) energy being carried away by the vapor molecule.
    The action at the individual molecule is more or less new to me. Engineers usually work with bulk properties of materials and statistical mechanics. Unless the engineer is working with something very very tiny like features on integrated circuits there’s never any need to consider what happens at quantum scales. I have a passing engineering interest in steam engines and have studied them from the first ones (which were invented to evacuate water from mine shafts) to present day construction. Steam is still used a lot today in industry because of its unique material properties the most attractive of which is its huge latent heat of vaporization which means you can move lots of energy from place to place with a small volume of an abundant non-polluting material. Along with steam engines I have a passing fascination with Carnot cycle engines in general. A convective cell is a heat engine which performs a lot of work moving large masses of air around and lifting a lot of water from the surface to high in the air and sometimes violently rearranging heavy objects on the surface like trees and homes and cows and automobiles.

  170. The bottom line for “sensitivity” to CO2 concentration is not simple thing. If the water cycle is stopped due to freezing temperatures then the sensitivity is very high and extraordinarily high for the first 0-50ppm where its greenhouse efficiency increases in a more linear fashion with increasing concentration. Much less sensitive to increases above 200ppm where it efficiency increases are inversely exponential.
    The earth without any greenhouse gases would have an average temperature well below freezing. CO2’s most significant role by far (excluding plants needing it) is in raising the surface temperature from below freezing to above freezing. Once that happens the water cycle is activated and as long as the temperature remains above freezing the water cycle controls the climate and CO2 does little to nothing. In the big picture then one might CO2 as a limiting factor in how far the average temperature can drop and the water cycle is a limiting factor in how far the average temperature can rise. Since the earth still periodically gets covered by glaciers for 100,000 years with brief respites lasting about 15,000 years then as far as civilization is concerned the “pre-industrial” CO2 level of 280ppm is too little as that doesn’t stop the recurring glacial epics. Maybe if we can manage one or two doublings from pre-industrial level by burning fossil fuels to get a CO2 concentration of 1000ppm (which will make green plants much happier too) it might be enough to break the glaciation cycle. What it won’t do is result in any excessive warming because the water is what limits warming. Sensitivity to CO2 doublings is essentially zero when and where the water cycle is active.
    The “correct” sensitivity is thus not anywhere near a fixed number but rather varies tremendously depending on the activity level of the water cycle which in turns depends only on surface temperature being on average above freezing.

  171. I don’t think sensitivity can be easily or convincingly explained to the average person. It doesn’t require any knowledge or skills that most people had when they managed to get passing grades on final exams in high school science classes. The thing of it is that most people forget that stuff very quickly because it isn’t needed in most cases to get along well in life. What the average person is good at and the skill grows with age and experience is knowing when someone is being dishonest and figuring out the ulterior motives that spawn the dishonesty. The public is becoming increasingly aware that catastophic climate disruption, or whatever the most popular name for it is today, is a big lie with a range of ulterior motives behind it mostly having to do with money and political power and keeping a largely useless cottage industry of climate related research alive and growing. I believe Climategate was the straw that broke the camel’s back. The average person might understand and accept that “trick” can just refer to a clever and useful way of doing something but when the trick is connected to “hide the decline” they understand that the trick in that case is a clever way of lying.

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