Determining the Correct Climate Sensitivity

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 Skeptic

CO2 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 Skeptic

Proposed 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 Skeptic

Climate 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 Skeptic

Proposed 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 Skeptic

GHE 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 Skeptic

Red: 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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Posted in Science Articles - Global Warming and Skeptic by inconvenientskeptic on October 24th, 2010 at 2:14 am.


This post has 24 comments

  1. Can I suggest to you that all this concern about climate sensitivity is misplaced? Ferenc Miskolczi used NOAA database of weather balloon observations that goes back to 1948 to demonstrate that the optical thickness of the atmosphere in the infrared where carbon dioxide absorbs remained constant at a value of 1.87 for 61 years. This means that the addition of carbon dioxide to the atmosphere for all these years had no influence at all on the transparency of the atmosphere for heat radiation from below.or the optical thickness would have increased, and this did not happen. To put it another way: the greenhouse signature of carbon dioxide is simply not there. Which means that the effect of doubling its concentration on global temperature is zero, not any of the finite numbers proposed. This is an empirical observation and overrides any theoretical calculations that seem to indicate warming. It is obvious that the theory needs to be revised. I myself have determined that the so-called “anthropogenic” global warming has never been observed and am inclined to think that Ferenc Miskolczi’s work may explain why this is so, Read “What Warming?” available on
    Ferenc Miskolczi E&E 21(4):243-262 (2010).

  2. inconvenientskeptic Oct 24th 2010


    While I agree that the forcing of additional CO2 is overstated, there is benefit to discussing the different aspects of the climate. The overall system is complicated which is why there is so much disagreement over the different issues.

    It is still worth understanding how sensitive the climate is to other potential forcings. Consider a different gas emission that did interfere with the open IR band. Understanding the future impact would be beneficial.

    For this specific case it is useful to see that the combined assertion that CO2 forcing and high climate sensitivity are clearly overstated. It is useful by itself to show that such the entire GHE requires large forcing values. That makes small forcing values much less likely to have a significant impact.

    I will be addressing the CO2 forcing separately in the future.


  3. Glenn Tamblyn Oct 25th 2010


    Where to start with this. Firstly I would like to point out generally that you are extrapolating values and formulae beyond their useful range and possibly getting some incorrect calculations. Finally your end calculations are based on a completely incorrect usage of what climate sensitivity means, at odds with your usage of it at the beginning of the post.

    Firstly a small point. You use the oft cited log function for radiative forcing for CO2 and then attempt to apply this. The value you use may be approximately correct but it is important to understand that the log formula is not a theoretical derivation. It is obtained by using radiative transfer calculations to calculate the radiative forcing for a wide range of CO2 concentrations. Then the 5.35 log function is the best curve fit to the derived results. The key paper on this is Myhre et al 1998 which is cited in the IPCC Third Assessment Report (TAR). Using this curve fit may not be completely reliable right down to very low concentrations. I don’t know if the 32 W/M2 figure at SkS is from applying this formula or calculated using something like ModTran.

    Next you are using the oft quoted figure of 30 DegC cooler without GH Effect. This is a number often cited. But wrt to our earlier conversation about the actual science verses reportage on the science, this is a figure cited FOR ILLUSTRATIVE PURPOSES ONLY. It is not exact. Not even remotely. Because it includes a major assumption! The calculation is

    – Solar Flux = 1366 W/M^2, average over the solar cycle
    – divided by 4 to convert from the Earths Cross Sectional area as presented to the Sun to the Earths surface area
    – Multiply by 0.7 to deduct sunlight reflected off the Atmosphere, top of clouds and the Earths Surface – the Earths total Albedo

    This gives 239 W/M^2

    The Stefan-Boltzmann Eqn is then used to calculate the black-body temperature of something that needs to radiate 239 W/M^2 out to space to remain in thermal balance.

    T = (239/(5.669 * 10^-8))^0.25 = 254.8 k = -18.3 DegC – 33 Deg cooler.

    Do you see the assumption? It assumes that the Albedo of the Earth when it is 33 Deg cooler will have the EXACTLY THE SAME REFLECTIVITY as it does today.

    If temperature conditions were 33 deg colder than present, how much greater will the ice cover be? If the last Glacial covered Canada, 1/2 the US, Europe & 1/2 of Russia, as well as extra sea ice, how much greater was the reflection of sunlight from the Earth then compared to now. And that was only about 8 Deg colder than now, not 33. What would ice cover be like in a world 33 Deg cooler?

    1/3 of the world doesn’t seem unreasonable to me. So Albedo of the planets surface, discounting atmosphere and clouds would be of the order of 0.33 * 0.1 + 0.67 *.08 = 0.57, not 0.7, not counting atmosphere and clouds. So perhaps 0.5 net.

    Plug that into the SB eqn and we get 53 DegC colder – -38DegC Average. At that temp, what would Ice cover be – 90%?. Plug that in and we get – 116 DegC, 131 Deg colder.

    Conceptually this is an iterative process to get some final value but whatever the final value, a world without GH gases would actually be much colder than the illustrative -18 DegC.

    So that part of your calculation is going to underestimate CS.

    Next you are assuming that CS is a single fixed value over all climate conditions.

    This isn’t valid.

    CS is an attempt to estimate how the climate, in its CURRENT CONFIGURATION will respond to a radiative forcing pressure. This may not be the same for forcings in both directions. And it most certainly will not be the same over all climate conditions.

    An ice free world will respond less to a heating pressure than a world at the bottom of a glacial. Similarly, a world with a bit of ice may respond more strongly to a cooling pressure compared to a world that is already at the bottom of a glacial. The sort of Snowball Earth that I illustrated would exist without any GH effect may only respond slightly to a warming pressure – if you have ice at -50, you still have ice at -40, so no albedo change. Only when warming has increased enough to trigger a decline of planetwide ice would CS start to climb as the climate now responds more strongly.

    CS is not a single fixed value so attempting to perform the calculation you are doing, assuming a single fixed value for CS across all CO2 concentrations, is rather strange.

    However, lets now take your argument at face value.

    You say “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 …. 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.” (my emphasis)

    Totally faulty reasoning or a statement of the principle that could easily be misleading John.

    The correct statement would be more like “CO2 FORCING MULTIPLIED by the magnifying feedback effects of other NON-FORCING FACTORS in the environment accounts for the 86% and the other 14% is due to Non-CO2 FORCING MULTIPLIED by the magnifying feedback effects of other NON-FORCING FACTORS in the environment”

    CO2 is 86% (your calc) of the Climate Forcing component of the GH Effect over its entire concentration range with non CO2 Forcings being 14%

    86% of the Forcing, NOT 86% of the total GH Effect. 86% before applying CS.

    And when you consider what that hypothetical Snowball Earth would be like, when it is that cold, Methane and Nitrous Oxide levels, both of which originate from plant biological factors, would be negligible and water vapour levels in such a climate would be low. In that situation CO2 is the only thing that can do the heavy lifting to produce that much warming. In our current climate however, Methane and Nitrous Oxide are significant components in any additional forcing. And water vapour is then an important multiplier. Its all about context.

    So your repeated contention that high percentages of the GH Effect for CO2 from your calculation can’t be right fall into the fallacy of assuming that the same conditions apply all the way through the concentration and temperature range. Wrong. CO2 most certainly can be the major forcing factor over much of the temperature range up from Snowball Earth because there were few other factors that would have an impact. Only in the last stages of this temperature range do other factors come into play. Your assumption of one CS value over the entire range leads you into this fallacy.

    Then you ‘work back’, adding together the forcing from CO2 & water Vapour to get a CS three times lower.

    Totally wrong.

    The feedback effects of Water Vapour are PART OF THE CS, as it is defined, not something being magnified by it. Although Water is a GH Gas, it is not considered a Forcing because it cannot accumulate and FORCE a change – if the article you read actually used the word ‘forcing’ that was an error of nomenclature. Its level in the atmosphere is determined by temperature. Something else has to force a temperature change that causes a change in water vapour levels that in turn causes more temp change.

    So your first calculation here is not applicable.

    Also a general note on how you are doing these calculations, simply dividing temp change by radiative forcing. Rather you should be looking at how a forcing alters the energy balance, doing the SB Eqn calc from both to get 2 temperatures and taking the difference. Essentially you are treating temperature as a linear change with forcing. OK as a approximate working figure over the smaller ranges we deal with today, but quite meaningless if you are projecting back through large ranges. SB is a 4th power equation and CS is not constant. So your calc’s are rather meaningless.

    Next you look at % contribution of CO2 to the GHE but don’t define whether this is % of the temperature change or % of the forcing. Since the SB eqn governs all of this that distinction is profoundly important.

    Then simply dividing the temp change by the CO2 forcing divided by the % is quite meaningless.

    Finally your use of the data from Kiehl, Trenberth 1997 is just plain bizarre. Your words “I get a total forcing from the surface to the atmosphere of 452 W/m2”

    Wrong!! Wrong!! Wrong!!

    You get a total RADIATION from the surface to the atmosphere of 452 W/m2. Forcing is a CHANGE in radiation, not the total magnitude. Remember that CS relates TEMPERATURE CHANGE to RADIATION CHANGE. So by your reasoning you are calculating the CS for a Radiation change from 0 W/M^2 to 452 W/M2. Since anything that is radiating nothing has to be at Absolute Zero, you are in effect calculating:

    (273.15+15)/452 = 0.6375.

    Even then you are not calculating a CS. Rather this is a strange convolution of the SB Eqn. Radiative Forcing applies to changes to the energy budget of the planet relative to its emissions to space, not relative to radiation from the surface.

    And since estimates of CS come from studies of a wide range of phenomena – the impacts of volcanic eruptions, ice cores, paleoclimate data, sediment studies, isotope studies etc and these are giving values within the accepted range, arguments for values at the bottom of the range might have validity, but arguments that go way below the accepted range from real world studies based on faulty arguments don’t carry much weight.

    Sorry John, but this really doesn’t cut it. I’ll give you the benefit of the doubt that this is honest endeavour – much of what appears in the denialosphere definitely isn’t honest – but if this was an undergraduate thermodynamics assignment, this would get an F

  4. inconvenientskeptic Oct 25th 2010


    I accept that 33 °C has validity, but the 131 °C colder is absolutely invalid. Projecting out albedo changes to justify a quadrupling of the GHE from the accepted values is avoidance.

    The argument that the CS for the current configuration has meaning, but for the current configuration my calculations are valid.

    The methods currently in use to determine climate sensitivity are flawed. They are based on the assumption that a temperature change (caused by forcing or natural variation) is only caused by a forcing. That method will always overstate the value of the climate sensitivity.

    For example. The climate sensitivity determined for the glacial/interglacial cycles assumes a change in overall global forcing for what is a local event. That approach is comparable to stating that the seasons are caused by the annual variation in the CO2 levels. The annual solar variation does not vary, only the local levels.

    I am arguing about the validity of methods for determining CS. I believe that the total GHE (30-33 °C, the difference is totally irrelevant to the results) is a much more valid place to determine the total impact of the forces exerted.

    As for your arguments about my use of forcing. That is a nomenclature argument. The Trenberth energy balance shows 452 W/m2 from the surface to the atmosphere. That I used forcing instead of energy is again not relevant.

    One item of interest. My CS estimates of 0.24-0.28 °C/(W/m2) are not far different than the results that that Stephen E. Schwartz got by using the heat capacity. His estimate was 0.3 °C/(W/m2). I actually believe that the 0.24-0.3 °C/(W/m2) is probably the correct value.

    The main point of this article is that the estimates of the CS do not align up with the total GHE. I strongly believe that the current methods of estimating CS are invalid. They require assumptions that are likely invalid.

    By the end of this week I will have 1-2 more articles that show how invalid the methods are when applied to the glacial/interglacial cycles.

    Consider the flipside. I will use 33 °C for a moment. Current projections for 2100 include are basically 3-6 °C increase in temperature. That is an 9-18% increase in the total greenhouse effect from a miniscule increase in the total energy involved. That is an indication that the CS is overstated.

    I know you can pull up the Realclimate “proof” that Schwartz is wrong. But it is easy to prove that the other estimates of CS are also wrong.

    Like I pointed out with the Taylor ice dome. CO2 increased for 10,000 years while temperature dropped for the last 6,000 years. Assuming that all the forces involved are correct and understood when we can’t even agree what is going on today is foolish.

    Partitioning the Total GHE is more likely to achieve an accurate climate sensitivity that assuming that a variation in temperature was caused by a forcing.

  5. Barefoot Dave Oct 25th 2010

    Very interesting. If IPPC’s 3 degrees C per CO2 doubling CS was correct, we should have warmed a good deal more than we have.

    One part of Glenn’s comment struck me as valid –to say the 3 degrees CS implies that that 86% of the GHE is due to CO2 and that is unreasonable seems wrong since the 3 degrees CS includes water vapor feedback, in theory with less CO2 the world will be cooler and there will be less water vapor.

    An allocation of the GHE % between CO2 and water vapor seems to be an accounting type problem given that both gases have a joint and overlapping influence on the GHE, how to do the allocation should depend on the question you want to ask.

    In other words, the fact that in our current atmosphere water vapor is much more powerful in its GH effect than is CO2, so CO2 is not 86% of the GHE today, does not seem to me to automatically reject any arbitrarily posited sensitivity factor.

    I look forward to reading your future posts on climate sensitivity, which is obviously central to the climate change debate.

  6. Crispin in Waterloo Oct 25th 2010

    @Glenn Tamblyn

    While you are very quick to point out what you think are fallacies I am actually a bit taken aback by how incorrect your lengthy analysis is.

    Water is a forcing and if there were no CO2 on the planet it would not be stupendously cold. It is in error to think that most heating comes from CO2. The ‘water is a feedback’ died years ago because it is so obviously not true. I understand that it is being revived again but it will not stand the test of basic physics. There is nearly no CO2 in the atmosphere now – I checked with a gas analyser. It’s warm. If it were as simplistic as claimed, the temperature of the world would have gone up significantly in the past 15 years.

    You list water as a only a positive feedback. There is a lot of evidence it is not very positive and may be negative once certain global temperatures are reached because of increase storm height – in fact it may already have reached that temperature range. I also thought that ‘only positive’ argument was beaten to death more than 5 years ago.

    The idea that we would be at -131 is silly. Below freezing ice and snow collect dust (from Earth and space) and after a time Earth would look like the moon – dark with water underneath. The main GHG in that case would be water vapour which sublimates from the ice even at very low temperatures.

    In general your comments are filled with parts of theoretical models and not grounded in real physics, in my view, though you say they are. Odd.

    Inconvenient Sceptic has used a very reasonable starting and finishing point for his CO2 ranging. As he points out, reality is different by a factor of 10 from the IPCC numbers. Why? I cannot see any way to create a discrepancy of 10 fold in his calculation. To attribute to water a strong enough positive feedback to account for a diminuition of the needed CO2 by 10-fold is beyond any standard atmospheric physics.

    H2O is the dominant force in the atmosphere and there would be lots of it at any temperature. I think it is important for you to update your arguments. Water on its own is strongly positive (on a snowball earth) and strongly negative above 24 C. That is why the earth was not warmer than 24 C when CO2 was 7000 ppm.

  7. John,

    Thank you very much for your clear article. I have linked to it from my page “Observatorio ARVAL – Climate Change; The cyclic nature of Earth’s climate”, at (The “Greenhouse Effect” section).

    Your blog is now linked from the four relevant pages in my website.

  8. A very provocative article, thanks.
    It helps to reveal how climate science is but in its infancy, and in no way fit to determine the future of the planet via multi-trillion dollar re-distributions and interventions into the global energy systems.

  9. Harold Pierce Jr Oct 26th 2010

    Hello John!

    Here are some comments I routinely post on various blog that are usually ignored and not understood by almost everbody especially climate scientists and IPCC.

    After analysis, the concentration for CO2 in a sample of local air is reported for purified dry air (PDA) which does not occur in the earth’s atmosphere and is comprised of nitrogen, oxygen, the inert gases , which are the fixed gases, and CO2. The composition of PDA (i.e., the relative amounts in PDA) is fairly uniform through out the atmosphere and is independent of location, elevation, pressure, temperature, and humidity except for minor local variations in particular with respect to CO2. This is the origin of the term “well-mixed atmospheric gases.”

    For PDA at STP (i.e., 273.15 K and 1 atm. pressure), there are presently about 390 ml, 17.4 millimoles, 766 mg, or 0.000766 kg of CO2 in 1 cubic meter. The density of PDA at STP is 1.29 kg per cubic meter.

    In real air there is no unifrom distributon of the masses of the various consituents including water vapor and clouds in space and time as is shown by daily weather maps of the various regions of the earth. High pressure cells have more mass of the gases but lower humidity than do low pressure cells, both of which move rapidly over the surface of the earth. Thus there is no uniform distribution of CO2 in the atmosphere. Air containing water vapor is less dense than dry air and has less mass of fixed gases and humidity is always quite variable.

    The metric used for CO2 in climate model calculations is ppmv and is incorrect. The metric that should be used is either mass per unit volume or moles per unit volume. Current climate models use the incorrect metric for CO2 and thus are fatally flawed.

    For interesting info and much useful data on the atmosphere and air, go to Universal Industrial Gases Inc.’s website at:

    There are tables that show the effects of temperature, humidity and pressure on the physical properties of air

    RE: The Positive Water Feedback Hypothesis

    At 14 deg C and 1 atm .pressure, 1 cu. meter of air has 12.1 g of water vapor for 100% humidity. If the temperature of the air is increased to 15 deg C, 1 cu. meter will now have 12.8 g of water vapor for 100% humidity , a small increase of only 0.7 g or 6.7% of water vapor. However, 100% humidity only occurs if it is raining or snowing or if there is dense fog. So how does the enormous amounts of surface water enter the atmosphere?

    The wind is the force that transports most of the surface water into the atmosphere and is far more important than simple evaporation of water in still air. When wind blows over a body of water, the surface will cool but water will still be transported into the air. Due to their momentum the much heavier nitrogen and oxygen molecules and argon atoms just blast the lighter water molecules out the surface water into the air. The lake effect is due to strong winds blowing warm surface water into the air and onto the usually colder land. Fans are used to keep us cool on hot days and nights.

    Changes in air pressure are also more important than a slight increase in air temperature as is shown on an aneriod barometer. An air pressure drop of an inch or so (ca 30 mm) of mercury will often cause rain or snow. If pressure increases, the air becomes dry. The heat of vaporization of liquid is depends mostly on external pressure. The low air pressure in tropical a cyclone cause enormous quantities of water to “flash evaporate” into the air as it moves into warm coastal water from the cooler open ocean.

    Clouds are liquid water in the air and depending on local temperature, pressure and humidity, they can readily release water vapor into the air or drop excess moisture as rain, snow or ice pellets. On average cloud cover in the atmosphere is about 65%.

    Clouds also contain atmospheric gases and can transport these, in particular CO2, from one local to an other local where these gases can be released into the air or be deposited on the surface in rain drops.

    Statellite images show there is no uniform distribution of the clouds and that they are always moving.

    Over land transpiration from plants contributes to the local humidity as does respiration from all plants and animals which includes soil organisms such as bacteria, fungi, worms and insects.

    Your calculations are not valid for real air and a Most of the various forcing constants are theoretical values obtain by calculation or estimated by statistical methods as was mentioned to me by Roy Spencer.

    I am an organic chemist [B.Sc. (Hon) , UI-UC, 1967; Ph.D., UC Irvine, 1972)., I and am quite surprised that you are unaware of the above and have made such errors.

    Now check this. Based upon the climate scientists’ computational speculations, conjectures and scenarios, I pay a carbon tax of Can $0.9932 per GJ of nat. gas which costs Can $4.976 per GJ in British Columbia. That is a 19.96% tax and 8 points greater than the sales tax on junk food (pop, chips ,candy, snacks etc).

    Go to the late John Daly’s website, “Still Waiting for Greenhouse” at

    and study the info and his arguments. You will quickly become skeptical and suspicious of the IPCC and its agenda and affilated scientists.

  10. inconvenientskeptic Oct 26th 2010


    The point of the this article was not to determine the actual climate sensitivity, but to use the commonly accepted values to show that the forcing values for CO2 are too high to fit within the commonly accepted value of the GHE. It was a consistency check of the accepted forcing, sensitivity and GHE. It failed that check.


  11. Harold Pierce Jr Oct 26th 2010

    Hello John!

    Wow! What a speedy reply! I really lke your choice of white text on the black background. It is so easy to read especially for me since I’m old guy, have fuzzy vision and don’t see too well.

    Why are you wasting time on the IPCC’s phony baloney because there is no such thing as CO2 forcing.

    Here is a comment I posted on Judy C blog a few days ago.

    Please do the following:

    1. Go to the late John Daly’s website “Still Waiting for Greenhouse” at

    2. On the homepage, scroll down and click on “Station Temperature Data.

    3. On the world map, click on USA.

    4. Under section “Pacific”, click on “Death Valley.”

    The chart is a plot of the temperature data from the weather station at Furnace Creek and is empirical data that falsifies the enhanced AGW hypothesis in the following way.

    A desert is an arid region of low humidity, a low biomass of plants and animals, little or no free standing or running water and mostly cloudless skies.

    After sunrise most of the sunlight is absorbed by the surface because there is little vegetation to block it. The absorbed sunlight is converted to heat, and the air heats rapidly by conduction and convection. Some of the heat escapes from the surface as out-going long wavelenght infrared radiation (OLR).

    After sunset the surface cools rapidly as most of heat is removed by conduction and convection. The air cools because there are no clouds to block the rising warm air and there little water vapor to absorb the OLR. If CO2 causes any warming of the air near the weather station, we would anticipate as slight but descernible increase in the annual mean temperature that should correlate with increasing the concentration of CO2. We do not know the actual atmospheric concentration of CO2 in Death Valley. We know only that it increase over time as indicated by the data from the Mauna Loa Observatory.

    The chart shows the temperature-time plots are essentially flat. Thus we conclude that CO2 causes little or no warning of the air in Death Valley which is the hottest and driest region in North America.

    In winter the air is more dense has a higher concentation of CO2 than in summer. Thus we might anticipate a greater slope of the winter plot compared to the summer plot if CO2 caused any warming of the air. Since the plots are parallel we can further concluded that CO2 causes no warming of the air.

    Many of the temperature-time plots of weather stations in desert and arid regions are similar to that from Death Valley suchas those in Tombstone, Dodge City and Utah.

    Here is what the reader should know. The climate scientists are well aware of John Daly and his website. They ignore his work because it is not “peer reviewed.” The Climategate emails reveal that boys at CRU were “elated” when he suddenly dropped dead from a heart attack

    I add these comments and suggetions.

    A plot of the annual mean temperature often shows large excursion from the mean which is attributable to “weather noise” and is in part due to the variation of sunlight over the course of year. We can eliminate the effects of sunlight by analyzing the temperatue data for one day for several selected days of the year such as the equinoxes and soltices. The Tmax and Tmin metrics should be analyzesd separately as recommend by Roger Sr. We can estimate value of weather noise by computing the classical deviation from the mean.

    We would anticipate that Tmin trend line should have slightly greater slope than that of Tmax since the air at Tmin is denser than that at Tmax if CO2 has any effect on warming the air for comparable air pressure.

    I have analyzed the temperature data of Sept 21 from the weather station at Quatsino, BC for the 1895 -2009 interval and have obtained a value of +/- 1.5 K for weather noise for both Tmax and T min. I also used an 11 day sample interval centered on Sept 21 and obtained the same value. This value of the weather noise is only valid for this weather station. The annual Tmean for 2008 is about 0.5 K lower than that for the 1895-1900 interval.

    It this value is similair for other weather stations, then there has been no or little global warming for the last 100 or so years.

    Would you like hard copy of my results?

    BTW, if you want to learn about any climate change, go and talk to the old folks in the rural areas. What do the guys in New York City really know about climate change?

    If you don’t want to pay punitive carbon taxes as we do in BC, you should really be tyring to show that the IPCC is indeed purpertrating scientific fraud. If a goverment can regulate CO2 emission and impose carbon taxes, it can not only seize control of the means of production but every aspect of your life.

  12. Glenn Tamblyn Oct 26th 2010

    “Projecting out albedo changes to justify a quadrupling of the GHE from the accepted values is avoidance.” No its not. The 131 DegC figure is illustrative of how much different the world would be due to albedo change. I can’t say it will be that. As Crispin pointed out, dust cover on the ice would be an issue. The point is that a world that has that much of a lower forcing due to ‘magicking away’ the CO2 will not be 33 DegC colder because that calculation assumes current Albedo. No matter what the final value is, a much colder Earth will be much whiter than the Earth currently is so in such a worldit must be significantly colder than -18.

    “The argument that the CS for the current configuration has meaning, but for the current configuration my calculations are valid.”

    I am afraid I disagree. You are attempting to perform a calculation to sanity check a real world number. But your calculation is based on projecting back conditions to a virtually CO2 free world but assuming Albedo won’t change and CS remains fixed over that entire range. This is a calculation you can do but what relevence does it have to the real world. This isn’t SimCity. Then you reject the conclusion of 86% CO2 contribution as unrealistic. But the model your calculation is based on is already

    “The climate sensitivity determined for the glacial/interglacial cycles assumes a change in overall global forcing for what is a local event”

    In what way is a glacial/interglacial cycle a local event? Weather patterns change all over the world during a g/ig cycle. Albedo change reflects more sunlight to space so less net absorption. Weather systems and ocean currents distribute heat all around the world. So significant ‘local’ energy balance changes get distributed all around the world to become global events and changes. So long as the studies being used to examine CS aren’t using primarily local proxies, then they will report on these global changes. Your particular focus seems to be the Ice cores, and as you pointed out in another post, the Temp’ record from the Ice Cores is based on isotope changes that are not local.

    Your still haven’t clarified whether the % of GHE you are citing are percentages of Temp change, or percentage of forcing. And your use of Water as something outside of the CS does not match the definition of CS. If you want to propose and alternative definition, fine, but you need to alter the established CS values by that factor of 3 as well.

    “Like I pointed out with the Taylor ice dome” We have already had a discussion about this on another thread.

    “Partitioning the Total GHE is more likely to achieve an accurate climate sensitivity”
    I totally disagree for the reasons I have stated.

  13. Glenn Tamblyn Oct 26th 2010

    Barefoot Dave
    “If IPPC’s 3 degrees C per CO2 doubling CS was correct, we should have warmed a good deal more than we have”

    Estimates of Climate Sensitivity are for what the Equilibrium change will be, not the instantaneous change. Since the Oceans have massively more thermal mass than the air, they haven’t warmed much yet. If we held GH Gases at current levels today, it would be decades before we reached thermal equilibrium.

    The standard estimate cited is that we have had 0.8 DegC warming of the air so far. When Thermal equilibrium is reached that would rise by another 0.6 DegC – 1.4.

    Also man made aerosols are providing an artificial cooling, estimated to be masking perhaps half the warming right now. Is that an additional 0.8 or 1.4. Dunno, so lets say 0.8. That gives us 2.2 DegC

    At current CO2 levels, we are less than half way to doubling. But applying the log eqn we are at around 1/2 the forcing expected so that implies a CS of 4.4.

    However this isn’t taking the change in the other GH gases into account. When these are included using their CO2 Equivalent values, we are at a CO2e level of around 430-440 today. Plug that into the Log eqn and we get 62% of the forcing from a full doubling – so CS of 3.5

  14. Glenn Tamblyn Oct 26th 2010

    Crispin in Waterloo

    Water is not a FORCING by the definitions used to define what CS means which is what this post is about. Water vapour levels do not change without prior temperature change (the Clausius Claperon Eqn) – They are not able to significantly accumulate or decline in the atmosphere without temperature so they cannot be the cause of initiating climate changes which is the meaning of the term Forcing. As such Water is the only GH gas defined as a feedback and not a forcing and thus is included in the CS. So the ‘water is a feedback’ never died, except perhaps in the blogosphere which isn’t worth much.

    My argument about much colder tempertures than -18 was to point out the fallacy John was making of assuming that albedo would be constant of the range of his thought experiment. As I said “Conceptually this is an iterative process to get some final value but whatever the final value, a world without GH gases would actually be much colder than the illustrative -18 DegC.” Your comment about dust has some validity but there is a very big difference between the Earth and Moon – an Atmosphere. Winds will continually scour the ice of the dust from space which is very fine and is easily blown around. In any less than full snowball Earth, this dust will eventually be blown into the areas of open ocean.

    Yes water vapour will sublimate from Ice, but it will also freeze out as well. The water vapour level in the atmosphere is governed by temperature so the amount will still be low and it requires something else to change that.

    As to your comment about 24 degrees when the CO2 levels was 7000 ppm, this is not the accepted explanation because you, like most sceptics when putting forward this point, are ignoring a major factor. Solar output was lower in the distant past, and higher CO2 levels were needed just to maintain the same temperatures. This was identified nearly 40 years ago as what is known as ‘The Faint Young Sun’ problem. When the Earth was young it had liquid water but the Sun was not hot enough to allow liquid water to exist on the early Earth. So something had to create a significantly greater temperature to allow liquid water to exist. A massive GH effect from a range of gases – CO2, Methane, Ammonia, and others – is put forward as the reason why the Earth didn’t freeze.

    The explanation of why Temps seemed to sit at around 24 DegC over long periods isn’t some negative feedback from water. It is that the Earth has a natural thermostat that adjusts CO2 levels over long timescales to compensate for Solar input changes – note I am talking 10’s of millions of years timescales, not short term stuff. This feedback mechanism is CO2 removal from the atmosphere by chemical weathering from rocks. CO2 reacts with water in the atmosphere to produce Carbonic Acid. This then rains out and washes Calcium and silicates from rocks forming things like Calcium Carbonate that wash down to the oceans and are slowly deposited on the sea floor, removing CO2 from the environment. And CO2 is released to the atmosphere by long term volcanic activity. This is the really long term carbon cycle, much longer term than things like the biological carbon cycle involving plants etc.

    So the amount of CO2 in the atmosphere in the very long term is the balance between sequestration due to Weathering and Volcanic emission rates. How does this make a thermostat? The Weathering reaction rate, like many chemical reactions,
    increases with temperature. So if CO2 levels and or Solar output rises causing heating, CO2 sequestration rates rise drawing CO2 levels down. If temp’s cool, the sequestration rate falls and CO2 levels can rise. Much like a Watt Governor on a steam engine, this acts as a natural thermostat. The only times when this thermostat fails and we get cooler conditions is when the configuration of continents pushes the world into Ice Age conditions such as the last 30 Million years, or a major sustained volcanic event temporarily overwhelms the thermostat triggering an ice age such as the Ordovician.

  15. Glenn Tamblyn Oct 26th 2010


    You are right to point out how uneven the distribution of water in the atmosphere is but this does not apply to anywhere near the same degree for the other components of the atmosphere
    . Satellite observations have recently reported some variations in CO2 level around the world but not anything like the variability of Water Vapour. And you seem to be confusing what happens at specific locations on the surface with what drives climate. Climate is by definition the long term average of weather – the WMO definition is on time scales of over 30 years. So ‘statistics’ are exactly what climate is. As to your discussion about Death Valley!!?? The major impact of GH gases is in determining the energy flux to space in the upper atmosphere, above around 10,000m. Relating CO2 levels in Death Valley to Weather in Death Valley is meaningless. Here in SE Australia we had some devastating bushfires nearly 2 years ago. A major cause of this was a large warm air mass at high altitude from Central Australia that descended to lower altitude, heating as a result. Weather Harold, not local CO2. Your comment “In winter the air is more dense has a higher concentation of CO2 than in summer. Thus we might anticipate a greater slope of the winter plot compared to the summer plot if CO2 caused any warming of the air. ” Wrong. You wouldn’t expect local variations based on local concentrations. And no the concentration doesn’t vary due to winter and summer. The air density varies but concentration doesn’t. At the somewhat higher density, mean path length before a radiated photon encounters an atom will be lower but the proportion of CO2 is unchanged.

    As for your statement about other molecules ‘blasting’ water from the ocean, and then relating this to using fans to cool ourselves? Fans cool us by providing a continuous stream of lower humidity air into which our sweat can evaporate and then have the higher humidity air blown away from us. If the humidity of the air is too high, a fan can’t cool us because no evaporation occurs.

    You said “It this value is similair for other weather stations, then there has been no or little global warming for the last 100 or so years.” But it isn’t similar Harold. it is different all over the world, including the sea surface temperatures. Thats why its called Global warming. looking at individual locations is meningless.

    “BTW, if you want to learn about any climate change, go and talk to the old folks in the rural areas. What do the guys in New York City really know about climate change?” How about going to speak to the Inuit and inhabitants of Siberia about the last time they had to abandon their homes because Permafrost melting had destroyed the foundations. Or the last time methane wea observed bubbling out of frozen lakes.

  16. T.G.Watkins Oct 27th 2010

    Very clear and interesting analysis. I fully understand you are using the IPPC arguments, assumptions and figures. A nice forensic dissection of the faulty arguments.
    I also enjoyed Harold Pierce Jnr. contribution.
    How to get all this into the MSM and to an honest politician?!
    Your site is excellent ; found you via WUWT.

  17. Jeffrey Eric Grant Nov 1st 2010

    I am an Engineer, but my Thermodynamics is a little rusty. I really enjoyed the post and the replies. I do have a background in Earth Science and have practical engineering experience in the Environmental and Energy Conservation fields.

    As a practical matter, why can’t the IPCC projections be analyzed to determine if they are close to what has actually transpired? I mean, from the 1999 Report, why can’t we just see how they did with their prognostications?

    Specifically, I want to know if the sea level will change say 20 feet in the next 100 years, when will Tuvalu be abandoned? When does Al Gore predict this will happen?

    Also, precisely, what actions need to be taken to mitigate the increased CO2 amounts — give me a “top 5” list along with who will pay for the actions.

    I have spent a lot of time contemplating what to do. Right now, I say we should continue to pour $Billions into the research and then take appropriate action when something happens which necessitates our actions.

    I do not subscribe to the theory that the consequences are so dramatic that we should take some action now, even though we have no proof that airborne CO2 concentration actually causes any calamity.

    Oh, BTW, if “half of the temp rise” has already been mitigated by the anthropogenic aerosols we have inadvertently put into the atmosphere, I say we should start there and put up twice as much. That should cover the problem (at least cost).

    The Earth’s Systems are so complicated and intertwined, we can’t possibly know enough to actually manage their functions. Look at China and how they have been unsuccessful in even managing their own weather. Climate is a chaotic system with thousands of parameters.

  18. inconvenientskeptic Nov 1st 2010


    I appreciate your comment. There is a lot that is understood. Weather is chaotic, but climate is less so. Winter in the NH will be colder than summer for very predictable and understood reasons.

    The main question is what impact will CO2 levels have on climate. That is where the correct sensitivity comes into play. If the climate is sensitive, then there will be trouble. If it is not sensitive, then there won’t be a problem.

    In many areas there are dramatic overstatements of potential consequences. Both sides have of the debate tend to focus on that which suits their arguments and that is what makes sifting the facts out so interesting.

    As an engineer you should enjoy some of the pieces I will be putting out soon. :-)


  19. Jeffrey Eric Grant Nov 2nd 2010

    Yes John, I do find this topic very interesting from a technical view. I do not find the politics of it interesting at all! For instance, I think what they tried to do at the last international Conference in Copenhagen despicable. Of course I applauded the result. I’d rather discuss the merits.

    I have been a weather bug my entire life. I grew up in Seattle (the first location where they tried ‘percent chance of rain’ as a better predictor than just ‘rain’ or ‘no rain’.

    Climate is built upon weather. Without weather, you have no climate. However, the changes we are seeing are so minute, one has a very difficult time discerning them. So, to a degree, we have to accept what the scientists are telling us. There is absolutely no way I can refute their arguments. They have the research money and i don’t; all I can do is read their results and critiques of their results.

    In these short notes we can’t state everything, but of course, I know we have made progress in the study of the system. Feedback is one of the areas that needs a lot of study. My point is that what we know is not much. In my scientific experience I was taught that the scientist who is trying out a new hypothesis has the burden of proof. That seems to be lacking in this field. Back in the seventies there was a call for Global Cooling and the beginning of a new Ice Age. Now it’s Climate Disruption, And, the definition is everything. To be heard over the din, one must shout at the top of your lungs.

    I am a ‘skeptic’ because I have not had the ‘aha’ moment. I am interested in learning the truth. I have been at this, one way or another. for a very long time. In a way, I want to believe; if they have not convinced me it is because I smell a rat. Now they have to overcome a lack of trust.

    Sorry, I’m still looking for the answers.

  20. inconvenientskeptic Nov 2nd 2010


    That is a good approach to take. That is where I was a while back. The book I have written is an overview of what I found about the climate. Hopefully I can get it published soon.

    The website will have some interesting pieces coming soon. In fact there will be one that you will enjoy soon. I try to make things simple, but retain a high degree of accuracy. :-)

  21. Richard Feb 26th 2011

    My knowledge of the climate (and skill in understanding it) are limited though I could have a lot to say about how data and code should be handled, tested and archived with detailed testing, change notes and history in a computerised world (which is my field).

    The main problems that I see with high sensitivity models are that, as far as I can tell, although everybody is good about telling us about the rise in temperature from increasing CO2 no-one seems to be prepared to state how and when this ‘forcing’ stops! How does it every get cooler?

    Low sensivity models (such as you are proposing) seem more likely to reversible and thus able to cool.

    Again, as far as I can tell, the actual measured temperatures are tracking very close to the IPCC ‘Constant Carbon Model’.

    If I was to paraphrase that instead as ‘Climate has a low sensitivity to CO2 concentration’ that would seem to suppprt the above conclusions that sensitivity to CO2 is low.

    I realise that this is a harsh paraphrase but I am certain that it is defensible. The ‘Constant Carbon Model’ assumes that no further CO2 is added to the atmosphere but that can reasonably be changed to ‘Adding extra CO2 has little effect’!

    A possible metric to test for CO2 sesitivity?

  22. Karl Disher Feb 28th 2011

    I’m kind of in Richard’s boat..directly above. I understand the basic discussion but I don’t want to put the effort John has into understanding this stuff on a level where I could be considered to know what the hell I’m talking about.

    Until someone gives me the theory behind why temperatures have ever cooled then I can’t really buy into the idea that CO2 is such a big factor in temperature change. I’m more into the glowing ball in the sky theory.

  23. RobbCab Jun 2nd 2011

    Pat Frank has an excellent essay on tAV ( that comes to roughly the same conclusion using different methods. His findings also seem to fit well with Sherwood Idso’s 1998 paper ( and though it doesn’t speak to climate sensitivity, Syun-Ichi Akasofy found a similar linear recovery from the LIA, with oscillations, that Pat alludes to (

    Maybe you should drop by tAV (or the WWUT cross-post) to add your two cents, as it would enhance the discussion.

    Also, with more researchers now coming to similar conclusions about climate sensitivity, I feel we (AGW skeptics) need a way to communicate verification of these hypothesis’ via independent analysis.

    Right now I feel as there are 1,000 voices screaming similar messages separately and no one can be heard against the background noise. We need to speak with one authoritative voice. Look how much the “Hockey Team” and the Climate Rapid Response unit have accomplished in focusing their message.

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