Guest essay by Dr. Antero Ollila
The highest ranked scientific journal Nature published on the 28th of July 2016 an article based on the survey for 1,576 researchers. More than 70 % of the researchers were not able to reproduce the results of another scientist’s experiments. Are there any attempts to reproduce IPCC’s climate sensitivity?
I think that the most important key figure of the climate change science is the value of the climate sensitivity (CS), because it describes the warming effects of the major greenhouse gas carbon dioxide (CO2). CS means the temperature increase corresponding to the doubling of CO2 concentration of 280 ppm.
1. IPCC’s estimates of climate sensitivity
IPCC still uses a very simple equation in calculating the global mean surface temperature response dTs (AR5, p. 664)
dTs = CSP* RF (1)
where CSP (also marked by lambda) is the Climate Sensitivity Parameter (K/(W/m2)) and RF is Radiative Forcing at the Top of the Atmosphere (TOA). IPCC says that the value of CSP is 0.5 K/(W/m2) and that it is practically constant. IPCC and many scientists as well calculate the RF value of CO2 by the equation of Myhre et al. (ref. 1):
RF = 5.35* ln(C/280) (2)
where the C is the CO2 concentration (ppm). The RF value of the CO2 concentration increase from 280 ppm to 560 ppm is 3.71 W/m2 (this value is called “the canonical estimate” by Gavin Schmidt et al. (2010)) and thus the CS = 0.5 K/(W/m2) * 3.71 W/m2 = 1.85 K. The value of TCS is between 1.0 to 2.5 Celsius degrees (later degrees) in the IPCC’s report AR5 and it means the average value 1.75 degrees (compare to 1.85 degrees). This means that the value of TCS by IPCC does not come out of blue but the equations (1) and (2) are still applicable. I limit the analysis of CS value only to this CS value, which is called transient CS (TCS) by IPCC. The calculation of the equilibrium CS (ECS) by IPCC applies positive feedbacks, which are not observed so far and are therefore very theoretical.
2. Some other estimates of climate sensitivity
There are many papers, which show lower CS than that of IPCC. I will summarize here some of them (the best estimate / the minimum estimate):
1. Aldrin, 2012: 2.0 °C / 1.1 degrees
2. Bengtson & Schwartz, 2012: 2.0 °C / 1.15 degrees
3. Otto et al., 2013: 2.0 °C / 1.2 degrees
4. Lewis, 2012: 1.6 °C / 1.2 degrees
5. Lindzen and Choi, 2011: 0.7 degrees
6. Idso, 1998, 0.4 degrees.
The four first studies uses IPCC’s or a GCM’s RF value without questioning it and therefore they are not real attempts to reproduce IPCC’s CS. None of these studies is based on the spectral analysis but they use the empirical temperature data. This methodology would work, if we could know the warming effects of all other warming elements like the irradiation changes of the Sun.
3. Climate sensitivity parameter – CSP
I have tried to reproduce the TCS value of IPCC using the same methods as IPCC but the result is not the same. I explain the calculations in sufficient details that a reader can follow the calculation method.
The simplest method for calculation of CSP is from the energy balance of the Earth by equalizing the absorbed and emitted radiation fluxes:
SC(1-a) * (¶r2) = sT4 * (4¶r2) (3)
where SC is solar constant, a is the total albedo of the Earth, s is Stefan-Bolzmann constant, and T is the temperature (K). The total RF value for the total area of the Earth is SC(1-a)/4 and therefore eq. (3) can be written in the form
4RF = sT4 (4)
When eq. (4) is derived, it will be
d(RF)/dT = 4sT3 = 4RF/T (5)
The ratio d(RF)/dT can be inverted transforming it to CSP
dT/d(RF) = CSP = T/(4RF) = T/(SC(1-a)) (6)
The average albedo value can be calculated from the observed reflected flux and the average solar irradiation values to be 104.2 W/m2 and 342 W/m2 = 0.30468. The temperature calculated by eq. (3) is
-18.7 degrees. According to Planck’s equation, this temperature corresponds to radiation flux of 237.8 W/m2 and it is also the observed flux value emitted by the Earth into space. Theory and practise are the same, when the theory is correct. According to eq. (6), CSP is 0.268 K/(W/m2).
There is a big difference between the CSP value of 0.5 K/(W/m2) and 0.268 K/(W/m2). The reason is well-known. The above calculations do not assume any changes in the absolute water content of the atmosphere. IPCC and the Global Climate Models (GCMs) assume a constant relative humidity (RH) in the atmosphere. It means that, when CO2 increases the global temperature and when the RH stays constant, the small increase of the absolute water content in the atmosphere increases the temperature. How much? IPCC writes in AR4 in section 8.6.3.1 that water vapor roughly doubles the response to forcing of GH gases and it is called positive waster feedback. In AR5 IPCC writes that water vapor’s contribution is approximately two to three times greater than that of CO2. I have checked that the doubling effect of water technically correct because water is about 12 times stronger a GH gas than CO2 in the present climate (ref. 6) but the question is if the RH is really constant in the atmosphere.
The observed RH values measured from 1948 to 2012 are depicted in Figure 1 and they and they show that RH values are not constant.
Figure 1. Relative Humidity graphs from 1948 to 2016.
It is obvious that the assumption of constant RH is not valid. Applying the CSP value of 0.268 K/(W/m2) and the RF value of 3.71 W/m2, the SC is 1.0 degrees, which is usually called Planck’s CS. As listed before, many researchers have applied different methods in calculating the CS value and a typical value is from 1.0 to 1.2 degrees. There is a good chance that these research studies have found this very same feature that there is no positive water feedback, which could double the RF value of 3.7 W/m2.
4. Radiative Forcing of carbon dioxide
IPCC uses the RF formula of Myhre et al. represented in eq. (2). The formulas of Hansen et al. (ref. 2) and Shi (ref. 3) give almost the same results as one can see in Figure 2. Eq. (2) of Myhre et al. is simple and easy to use. It is a kind of standard as a measure of CO2 warming effect and it is called even “and iconic formula”.
Figure 2. The RF values of CO2 according to Myhre et al., Hansen et al., Shi, and Ollila.
The first hint about the problems of this formula comes from the paper of Shi published in 1992 in journal by name “Science in China – Series B”. It is not available through network and I have received a personal electronic copy from the author himself. In Figure 3 is a print screen from a sentence, which states that the author has used a fixed RH value in his calculations. This means that the water has doubled the RF value of CO2.
Figure 3. The RH assumption of Shi.
The only way to find out the real RF relationship is to carry out the CS calculations according to the specification of CS (ref. 4). I have used the application Spectral Calculator available through Internet and this software uses Line-By-Line (LBL) method. A very essential thing is to use the Average Global Atmosphere (AGA) profile of the Earth for the temperature, pressure and humidity. I have combined the AGA profile from the five climate zones of the Earth (available in Spectral Calculator), which has the TPW (Total Precipitated Water) value of 2.6 cm and the surface temperature of 15.0 degrees.
First I have calculated the OLR (outgoing longwave radiation) at the TOA for the CO2 concentration of 280 ppm. The OLR is the sum of emitted radiation by the atmosphere 183.8 W/m2 and the transmittance (the portion of the surface emitted radiation not absorbed by the atmosphere) 81.6 W/m2, together 265.4 W/m2. When the CO2 is increased to 560 ppm, the same radiation values are: emission 183.4 Wm2 and transmittance 79.2 Wm2, together 262.7 W/m2. Now we can see the effects of increased absorption caused by the increased concentration of CO2; the OLR has decreased as it should happen according to the theory of GH effect. Because the Earth obeys the first law of energy conservation, the ORL must increase to the original value of 265.4 W/m2. The only way this can happen, is the higher surface temperature of the Earth. By trial and error, I have found that the temperature 15.66 degrees gives emission rate of 185.0 W/m2 and transmittance of 80.4 W/m2, together 265.4 W/m2.
Because the cloudy sky calculations are not possible in Spectral Calculator, I have calculated the clear and cloudy sky values by the MODTRAN application. These results show 30 % lower OLR change than the clear sky. IPCC reports that the reduction is 25 %. Using the MODTRAN figures, the result is that the TCS value is 0.56 degrees and CSP is 0.259 K/(W/m2). The CSP value is very close to the Planck’s CSP = 0.268 K/(W/m2).
The original study of mine is published in 2014 in Development of Earth Science by title “The potency of carbon dioxide (CO2) as a Greenhouse gas” (ref. 4). My formula for the RF of CO2 is
RF = 3.12 * ln(C/280) (7)
The warming values of CO2 according to eq. (7) is depicted also in Figure 2. It is about 50 % lower than the graph of Myhre et al. In Figure 2 is also depicted a modified curve of Myhre et al. and it is done by multiplying the values of the original formula by 0.5 for eliminating the assumed water effect. This curve is fairly close to the curve depicted by eq. (7).
My CS calculations according to its specification and the text of Shi shows that the RF value of CO2 calculated by eq. (2) of Myhre et al. can be explained, if the warming effects of water are included by assuming the constant atmospheric RH conditions. There is also another possible explanation for the eq. (2). Myhre et al. have used in calculations water vapor and temperature data from the European Centre for Medium-Range Weather Forecast. This data is not publicly available and it is impossible to check what is the average global TPW value of this data.
The conclusion is that the IPCC’s warming values are about 200 % too high (1.75 degrees versus 0.6 degrees) because both the CO2 radiative forcing equation, and the CS calculation include water feedback. It is well-known that IPCC uses the water feedback in doubling the GH gas effects; even though there are relative humidity measurements showing that this assumption is not justified. CO2 radiative forcing by Myhre et al. includes also water feedback, and this has not been recognized before the author’s studies. This feature explains too high of a contribution of CO2.
5. Validation of results
Firstly, I want to show that my spectral calculations are correct, if compared to some other published results. Kiehl & Trenbarth (ref. 6) have published in 2009 an article, in which is probably the most generally used Earth’s energy balance presentation. In the LBL spectral calculations they used U.S. Standard Atmosphere 76 atmospheric profiles. They reduced the absolute water amount TWP by 12 %. Using this atmosphere, they calculated that the warming contribution of CO2 in the clear sky is 26 %; Also, this results is probably the most referred figure about the strength of CO2 as a GH gas.
I have reproduced this calculation by using Spectral Calculator and my result is 27 % – close enough. There is only one small problem, because the water content of this atmosphere is really the atmosphere over the USA and not over the globe. The difference in the water content is great: 1.43 prcm versus 2.6 prcm. I have been really astonished about the reactions of the climate scientists about this fact. It looks like that they do not understand the effects of this choice or they do not care. Which alternative is worse? The real contribution of CO2 in using the right TWP value is 13 % (ref. 7 ).
My LBL spectral analysis is based always on the calculation of the total absorption, transmission or emission in the atmosphere. For example, the effects of GH gases are based on the variations of their concentrations. Stephens et al. (ref. 8) has summarized the results 13 of studies based on the observed values of the downward LW radiation by the atmosphere right on the surface of the Earth. The results vary from 309.2 to 326 W/m2 and the average value is 314.2 W/m2. My calculation gives the result of 310.9 W/m2, which differs 1 % from the average observed value and it is well inside the error margin of +/- 10 Wm2, which is estimated accuracy of measured LW fluxes.
References
1. Myhre, G., Highwood, E.J., Shine, K.P., and Stordal, F. 1998. “New estimates of radiative forcing due to well mixed greenhouse gases.” Geophys. Res. Lett. 25, 2715-2718. http://onlinelibrary.wiley.com/doi/10.1029/98GL01908/epdf
2. Hansen, J., Fung, I., Lacis, I., Rind, A., Lebedeff, D., Ruedy, S., Russell,G., and Stone, P. 1998. “Global Climate Changes as Forecast by Goddard Institute for Space Studies, Three Dimensional Model.” J. Geophys. Res., 93, 9341-9364. https://pubs.giss.nasa.gov/abs/ha02700w.html
3. Shi, G-Y. 1992. “Radiative forcing and greenhouse effect due to the atmospheric trace gases.” Science in China (Series B), 35, 217-229. Not available online.
4. Ollila, A. 2014. “The potency of carbon dioxide (CO2) as a greenhouse gas”. Dev. Earth Sc., 2, 20-30.
http://www.seipub.org/des/paperInfo.aspx?ID=17162
5. Kielh, J.T. and Trenbarth, K.E. 1997. “Earth’s Annual Global Mean Energy Budget.” Bull. Amer. Meteor. Soc. 90, 311-323. http://journals.ametsoc.org/doi/pdf/10.1175/1520-0477%281997%29078%3C0197%3AEAGMEB%3E2.0.CO%3B2
6. Ollila, A. 2017. “Warming effect reanalysis of greenhouse gases and clouds”. Ph. Sc. Int. J., 13, 1-13. http://www.sciencedomain.org/abstract/17484
7. Stephens, G.L., et al. 2012. “The global character of the flux of downward longwave radiation”. J. Clim., 25, 2329-2340. http://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-11-00262.1
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Donald. One more addition. IPCC assumes that the RH is constant. It means that when CO2 increases the temperature, the RH will remain constant. It does sound a big thing. But it means that in a higher temperature, the absolute amount water has increased a little bit. This small increase of absolute water has the same warming impact as by CO2. It means that water must be very powerful GH gas. And it is. I have checked this feature and I found that this time IPCC calculates the warming effect of water exactly correctly. This is possible only if water is about 12 times stronger that CO2.
Why has AGW science and its flawed models continued to survive despite model/observation divergence, no increase in humidity, no troposphere tropics hotspot and other evidence that the IPCC has got it wrong?
Where is the blockage in showing that the official science is flawed? It is the case that much of the evidence is negative in the sense that model predictions have not been confirmed, there is no evidence to support them. Negative evidence is still evidence.
Is it simply a political problem in that governments ignore the evidence or lack of it. Until now, perhaps in the US.
The flaw is one of groupthink ignoring multidecadal oscillations such as AMO and possibly a loosely-linked Pacific one of multiyear-smoothed imbalance between El Ninos and La Ninas. The CMIP5 climate models were tuned to hindcast what happened in its “historical” period, which is before the transition from 2005 to 2006. And especially the rapid warming period from 1975 to 2005. Meanwhile, I figure about .2 degree C of the warming from 1975 to 2005 was from a natural multidecadal cycle, but modeled as being manmade. I expect that if a correction of climate models gets made for this, then they would have erred much less. Including how global temperature trended and will trend during The Pause/Slowdown, and predicting only a fraction as much tropical upper tropospheric warming hotspot as the climate models that are failing in that area now.
“I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most obvious truth if it be such as would oblige them to admit the falsity of conclusions which they delighted in explaining to colleagues, which they have proudly taught to others, and which they have woven, thread by thread, into the fabric of their lives.”
– Leo Tolstoj
Here is section 3 from my blogpost Aug 2015 at http://climatesense-norpag.blogspot.com/2015/08/the-epistemology-of-climate-forecasting.html
“3. Ava says -It looks like the Earth is going to cool down- Why is my teacher and President Obama saying the earth is going to get very hot and the Polar Bears are all going to die unless I walk to school ?
Well Ava – I would have to write a book to explain how so many different people came to be so wrong for so long about so much- sometimes with the best of intentions. Here is a short story telling what happened.
In 1968 a man called Ehrlich published a book called the Population Bomb. He thought the number of people on earth was growing so fast that there soon wouldn’t be enough food to feed everybody, He said in the book.
” In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate”
Some people at the time got very worried and put their guesses about such things as future population growth, food production ,oil supplies, industrial production and mineral reserves into a computer program.. They intended to look at possible future problems and also explore the possibility that the peoples and governments of the earth could agree on a way of running the worlds economy that could be sustainable, that is, go on for a long time. They put all this in a book called The Limits to Growth published in 1972.
A very energetic business man called Maurice Strong who knew a lot of very influential people persuaded the United Nations that, as he himself believed and indeed still strongly believes, this sustainability problem was very serious.The UN and Sweden organized a meeting in 1972 in Stockholm to discus the interaction of humans with the environment. Strong was appointed by his UN friend U Thant , to be the General Secretary of the meeting. Strong, by nature, is very determined and action oriented and he and the conference produced an incredibly detailed 109 point action plan designed to give the UN input and even control over individual Government environmental policies world wide. As one of the actions, the United Nations Environmental Program ( UNEP) was organized in 1973 with Mr Strong himself as Executive Director.
Ten years later it was obvious that the predictions of imminent death and disaster were wrong. The people at UNEP still wanted to take global control of the worlds economy. They realized that if they could show that the CO2 ( carbon dioxide) produced by burning coal and oil to make electricity and drive our cars might cause a dangerous warming of the earth they would be able to scare the Governments and people into writing laws giving the UN ( and them) control over the world’s economy by controlling the type of energy used and its price.
UNEP organized a meeting of scientists at a place called Villach in Austria in 1985 to see if they could show that CO2 was dangerous. The scientists said
“Although the observed global-scale warming experienced over the past ~100 years is compatible with model estimates of the magnitude of the greenhouse effect, unequivocal, statistically convincing detection of the effects of changing CO2 and trace gas levels on climate is not yet possible. An important problem in the positive identification of a greenhouse gas effect on climate is to explain the medium to long time scale (~decades or more) fluctuations in the past record. Attempts to model such changes have, to date, suffered from a number of deficiencies.”
Ava – In other words they couldn’t prove any effects of man made CO2 on climate.
But whoever wrote the official summary statement and recommendations said:
“As a result of the increasing concentrations of greenhouse gases, it is now believed that in the first half of the next century a rise of global mean temperature could occur which is greater than any in man’s history. ”
The report made two important recommendations. As a result of one ,the Intergovernmental Panel on Climate Change was set up to select from the evidence and from time to time produce reports which would show that CO2 was the main driver of dangerous climate change and a second recommendation resulted in a meeting in Rio in 1992 chaired by Maurice Strong himself which produced the United Nations Framework Convention on Climate Change , later signed by 196 governments.
The objective of the treaty is to keep greenhouse gas concentrations in the atmosphere at a level that they guessed would prevent dangerous man made interference with the climate system.
This treaty is really a comprehensive, politically driven, political action plan called Agenda 21 designed to produce a centrally managed global society which would control every aspect of the life of every one on earth.
It says :
“The Parties should take precautionary measures to anticipate, prevent or minimize the
causes of climate change and mitigate its adverse effects. Where there are threats of serious or
irreversible damage, lack of full scientific certainty should not be used as a reason for postponing
such measures”
In other words if the models show there is even a small chance of very bad things happening the Governments who signed the treaty should act now to stop it. But how good are the computer Models?
The successive five reports of the IPCC in the Summaries for Policymakers written by Government representatives have clamed increasing certainty for the outcomes of their Model based projections of future temperature which is not supported by the Science sections of the reports or the actual data.
Remember the Villach meeting said
“in the first half of the next century a rise of global mean temperature could occur which is greater than any in man’s history.”
All the models and projections made since 1985 were built in the assumption that CO2 was the main climate change driver- for that and for many other reasons they are in reality useless for forecasting future temperatures. A new forecasting paradigm is required – see http://climatesense-norpag.blogspot.com/2017/02/the-coming-cooling-usefully-accurate_17.html
Typo: Trenbarth should be Trenberth
Dr Ollila
Thank you very much for one of the most interesting and stimulating posts I have seen on this blog. I even understand some of it and I’m very impressed by the overall grasp you have of these matters.
Others have posted on the subject of errors resulting from the assumption of constant RH used in the basic IPCC presentation. It has been argued in response that the models only assume constant RH as a means of deriving the intial relationships to be used, but that actual RH, and indeed ECS, drops out as a result of model runs. I don’t have the math to identify the real point of issue here, am thoroughly confused, and so far I haven’t seen your argument put to the test. I might hope for a contribution to this from Nick Stokes, Steven Mosher, and perhaps Nic Lewis. The first two, whilst not exactly in the warmist camp, provide an antidote to some of the shallower sceptical comments we often see. I hope they’ll post.
I myself have long cherished – the ‘null hypothesis’ if you like – the idea of a negative water vapour feedback. Seems to me self-evident. However, it could be that this would operate only in the tropics. At high latitudes increased evaporation/convection could not so easily counteract the GH effect of CO2, so that there is room for a polar driver on temperature which the models may be emulating in a way that globally averaged physical calculations cannot? There is certainly observational evidence that this is what happens. Excuse my clumsy way of describing it: I’m only a biologist//
“and so far I haven’t seen your argument put to the test. I might hope for a contribution to this from Nick Stokes, “
I can’t make any progress. The basic assertion here is
“IPCC says that the value of CSP is 0.5 K/(W/m2) and that it is practically constant.”
and I can’t find anywhere that they said that. I asked above, to no useful effect. What is needed is a proper quote. What did they actually say? Where? Then we can argue about whether it is right. I don’t believe that statement is an accurate statement of the IPPC view.
Nick Stokes. Here is the direct quatation from AR5. I have copied the text from AR5 and changed the Greek symbols to English in the text. The quotation starts and ends with + signs:
++++++++++++++++++++++++++++++++++++++++++++++++++++
IPCC, AR5, 8.1.1.1 Defining Radiative Forcing
Alternative definitions of RF have been developed, each with its own advantages and limitations. The instantaneous RF refers to an instantaneous change in net (down minus up) radiative flux (shortwave plus longwave; in W/m2) due to an imposed change. This forcing is usually defined in terms of flux changes at the top of the atmosphere (TOA) or at the climatological tropopause, with the latter being a better indicator of the global mean surface temperature response in cases when they differ.
Climate change takes place when the system responds in order to counteract the flux changes, and all such responses are explicitly excluded from this definition of forcing. The assumed relation between a sustained RF and the equilibrium global mean surface temperature response (dT) is
dT = CSP*RF
where CSP is the climate sensitivity parameter. The relationship between RF and dT is an expression of the energy balance of the climate system and a simple reminder that the steady-state global mean climate response to a given forcing is determined both by the forcing and the responses inherent in CSP.
In both the Third Assessment Report (TAR) and AR4, the term radiative forcing (RF, also called stratospherically adjusted RF, as distinct from instantaneous RF) was defined as the change in net irradiance at the tropopause after allowing for stratospheric temperatures to readjust to radiative equilibrium, while holding surface and tropospheric temperatures and state variables such as water vapor and cloud cover fixed at the unperturbed values. RF is generally more indicative of the surface and tropospheric temperature responses than instantaneous RF, especially for agents such as carbon dioxide (CO2) or ozone (O3) change that substantially alter stratospheric temperatures. To be consistent with TAR and AR4, RF is hereafter taken to mean the stratospherically adjusted RF.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
This quotation confirms the radiative forcing concept of TAR and AR4 by referencing them.
An eyes opening table is in AR5, Table 9.3, page 818. It is a summary of 30 CMIP5 AOGCMs, i.e. the latest and the most complicated computer climate models. The model mean values are as printed in the Table 9.3: Effective Radiative Forcing (ERF) 3.4 W/m2, ECS 3.2 degrees, TCS 1.8 degrees, CSP 1.0 K/(W/m2). The ERF value 3.4 is slightly smaller than that of IPCC 3.7. The CSP value in this case is applicable in calculating the value of ESC and it is practically same as in calculating the ECS according to IPCC’s model dT = CSP * RF = 1.0 * 3.7 = 3.7 degrees. This can be compared to the ECS reported by IPCC in the range from 1.5 to 4.5 degrees and the average being 3.0 degrees.
If IPCC reports CSP values of GCMs, it is justified to talk about the CSP and RF values of the simple model of IPCC. IPCC has not rejected the concept of the radiative forcing and the CSP value of 0.5 K/(W/m2) is still the best average value, which can be found in calculating TCS. If somebody says that it not so, he/she has to show, what is the real concept of IPCC for radiative forcing. I just remind that the calculation of the total RF value has always been the key information in SPM (=Summary for Policymakers). What is the meaning of RF, if somebody cannot calculate the corresponding surface temperature change? Nice to know? What can a policymaker do with a RF value?
“Here is the direct quatation from AR5.”
Yes, but it doesn’t include anything that supports your key assertion:
“IPCC says that the value of CSP is 0.5 K/(W/m2) and that it is practically constant.”
I keep asking – where does the IPCC say that? You keep coming up with places where they aren’t saying it. It’s what you want people to reproduce – where did they say it?. 0.5. Practically constant. You just haven’t supported that in any way. Now you say
” the CSP value of 0.5 K/(W/m2) is still the best average value”
Sounds like it is your value, not the IPCC’s. Don’t give endless irrelevant pages from AR3-5. Quote their words where they say it.
Where does it say it lower Nick ? And if it’s lower doesn’t that change the outcome of the models ? 2 to 3 times of an over estimation is substantial.
Here is the copy from TAR.
+++++++++++++++++++++++++++++++++++++++++++
IPCC, TAR:
6.2 Forcing-Response Relationship 6.2.1 Characteristics
As discussed in the SAR, the change in the net irradiance at the tropopause, as defined in Section 6.1.1, is, to a first order, a good indicator of the equilibrium global mean (understood to be globally and annually averaged) surface temperature change. The climate sensitivity parameter (global mean surface temperature response dTs to the radiative forcing dF is defined as:
dTs/dF = CSP (6.1)
(Dickinson, 1982; WMO, 1986; Cess et al., 1993). Equation (6.1) is defined for the transition of the surface-troposphere system from one equilibrium state to another in response to an externally imposed radiative perturbation. In the one-dimensional radiative-convective models, wherein the concept was first initiated, CSP is a nearly invariant parameter (typically, about 0.5 K/(Wm-2); Ramanathan et al., 1985) for a variety of radiative forcings, thus introducing the notion of a possible universality of the relationship between forcing and response. It is this feature which has enabled the radiative forcing to be perceived as a useful tool for obtaining first-order estimates of the relative climate impacts of different imposed radiative perturbations.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
It seems to be a misunderstanding. The model-mean of CMIP5 gives a TCR of 1.85 which translates to a warming due to CO2- forcing ( with 3.71 K per doubling) of 0.5K/W/m². So it’s definitely not a value of IPCC but a value calculated from CMIP5-mean.
Typo-correction: 3,71 W/m² NOT K
frankclimate. The “model mean” of TCR as it is called in AR5 in Table 9.5 is not 1.85 but 1.8 degrees (mean of 30 GCMs). The TCR calculated by using equation (1) and (2) = 0.5 * 3.71 = 1.85 degrees. Surprisingly close to each other but calculated on the different ways. As I have explained, the reason is probably that GCMs use Myhre’s equation..
Isn’t it is reassuring that the science seems so unsettled ? Mind you this from a shallower sceptical deplorable denier perspective . I do accept climate change and really like warming too. I didn’t need the debatable formulas though because as soon as Al Gore and Hollywood actors got involved the debate was over for me . Nice to see real scientists discuss the issues though . Maybe they can now be less intimidated and unafraid to admit there is much to learn about the very important field of climate science .
Dr Ollila, thank you so much for, after a few weeks of childish political posts in this “once great” blog, post a real interesting text about climate science.
According to AR5 of IPCC by doubling of CO2, global warming rises to 1.75 oC and according to the present author it is 0.6 oC. However, in such estimations the following three aspects must be taken in to account.
1. Sunspot’ Activity:
I made studies using power spectral analysis in 1975 with Lower Stratospheric Meteorological data height (H), temperature (T), zonal wind component (u) & meridional wind component (v) at 100, 50 and 30 mbar levels for individual stations in the latitude belt 13o 5’N to 12o 0S for the period Jan. 1964 to Mar. 1974. H, T and u showed long period waves at all levels with few exceptions. In the case of v. the long period waves are more prominent at 50 and 30 mbar levels compared to 100 mbar level. As the distance between station and the equator increases, the annual cycle is seen even from low level onwards. Enhancement due to Sunspot activity is more prominent on H than on T, u & v. Singapore and Lima show drop in H with increasing sunspot activity and the opposite feature is seen at Bogota and Malakal. This suggests that these variations may be of an oscillatory type parallel to the longitude circle. T shows opposite phase variations at 100 and 50 mbar levels. This type of variation is also seen at higher levels at low sunspot activity period, more prominently away from the equator. Generally, a drop in temperature is seen with increasing sunspot activity, except at Malakal at 50 mbar level, where it is opposite. As in T, u also shows opposite phase variations at 100 and 50 mbar levels. The parameters u and v show respectively change from westerly to easterly and northerly to southerly with increasing sunspot activity. T shows decrease in temperature with increasing sunspot activity. [S. Jeevananda Reddy & (Miss) S. N. Lahori, 1977, Indian Journal of Radio & Space Physics, 6:51-59 – presented at the Symposium on Eart’s Near Space Environment, 18-21 February 1975, NPL, New Delhi].
Power spectrum analysis was carried out using the 21 stations data series of global solar radiation and 8 stations data series of net radiation.The total solar radiation and net radiation intensities show sunspot cycle. This clearly indicates the influence of sunspot cycles on solar and net radiation intensities. Therefore, it is suggested that during the sunspot cycle period there is certain change in the solar radiation emitted by the sun itself; which in turn, is reflected in other atmospheric processes also. Both presented an increasing trend after 1940s at some industrial stations. It is more pronounced in net radiation due to air pollution related urban heat island factor. [S. Jeevananda Reddy, O. A. Juneja & (Miss) S. N. Lahori, 1977, Indian Journal of Radio & Space Physics, 6:60-66 – presented at the Symposium on Eart’s Near Space Environment, 18-21 February 1975, NPL, New Delhi].
2. Global Warming component:
According to IPCC, global warming started around 1951. Global average temperature presents the trend and superposed over it the 60-year cycle [moving average also show this]. The trend [0.6 oC/Century during 1880-2010] consists of (1) greenhouse effect and (2) non-greenhouse effect. According to IPCC, the former is more than half wherein it consists of component associated with anthropogenic greenhouse gases, known as global warming since 1951 and aerosols component. If we take global warming as half then it is 0.3 oC/Century.
Non-greenhouse effect is over emphasized in the global average temperature trend due to uneven distribution of met network. This is rectified in the satellite data series. This trend shows less than half of the ground based data. Thus, the global warming is half of 0.3 oC/Century [0.15 oC/Century].
3. Sensitivity factor:
In nature when energy is limited, the conversion of energy in to temperature by doubling of the CO2 may not follow the pattern defined by the IPCC or for that matter the present article author. This follow classic sigmoid pattern – slow rise [near flat] followed by steep rise followed by slow rise [near flat].
With this, we cannot take it granted the global warming raise a stereo type rise per Century but it tappers-off with the increasing CO2.
Unfortunately, some scientific groups associated with Warmist’s groups are manipulating rainfall data.
Dr. S. Jeevananda Reddy
A comment about the Paris climate agreement COP21. The goal of the agreement is to keep the warming below 2.0 degrees from the year 1750 and even below 1.5 degrees. The present CO2 emission rate is 10 GtC/y corresponding the average growth rate of 2.2 ppm CO2 per year. With this rate the IPCC model (CSP = 0.5 K/(W/m2)) calculated temperature increase would be 2.0 degrees in the end of this century. No CO2 emission reductions needed.
Because COP21 agreed on the drastic emissions reductions, it means that IPCC and UN have used the higher value of CSP = 1.0, which would give the temperature increase of 3.9 degrees in 2100. This would mean cutting the CO2 emissions about to the level 6.5 GtC/y from the present 10 GtC/y.
Looking at the scientific basis of this agreement, it is impossible to find. There is one outcome that the agreement “leads to a projected level of 55 gigatonnes in 2030”. The gigatonnes are probbally CO2 corresponding to 15 GtC. What does this figure mean? I do not find any explanation. I am sure that the decision makers had no glue about the science behind the agreement.
Climate sensitivity more properly refers to the emotional disposition of believers in catastrophic human-caused climate change. These people are very sensitive to being questioned about their legitimacy.
A high sensitivity is indicated by totally dismissive cursing.
A low sensitivity is indicated by passive aggressive sarcasm.
(^_^)
I have spent the better part of two days learning from this. I want to thank the author for all the time and effort put into detailing his methods and calculations. And also responding to the commenters who had serious responses [and letting those critics who really were not responding to the post at all slide off to the side, that takes fortitude]. In the process of attempting to make sure I understood this [ie: googling certain terminology], I also happened upon an older paper [pre-IPCC, 1967] that seemed, by different methods, to arrive at about the same conclusion. http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(1967)024%3C0241%3ATEOTAW%3E2.0.CO%3B2 What an education this is! Dr. Antero Ollila, if you ever find yourself traveling to Minnesota, please alert me. I at least owe you a lunch.
Randy Bork. Thank you for your nice words and invitation. Who knows.
I am sorry about the typing and grammatical errors. Especially the word “water” turned out to be difficult. The reason seems to be my little finger. It strikes too easily a and s at the same time, because s is next to a.
Thank you for your patience.
“Because the Earth obeys the first law of energy conservation, the ORL must increase to the original value of 265.4 W/m2. The only way this can happen, is the higher surface temperature of the Earth.”
There are other ways this can happen. From satellites ~70km altitude, the CO2 fundamental bands are seen radiating at the Planck temperature of the tropopause. We are talking about CO2. It is often posited that the “effective radiative level” is increased with increasing concentration. At the tropopause the lapse rate inverts and higher altitudes radiate at higher temperatures. Radiation to space therefore increases to the fourth power of whatever temperature increase the higher radiative level affords.
gymnosperm. If this is so that the temperature of the stratosphere defines the OLR flux, why the OLR flux of 239 W/m2 corresponds to the temperature of -19 degrees and not the higher temperatures of the stratosphere? There is even higher temperatures in the thermosphere. What about these temperatures affecting the radiation flux amount?
All very good questions. I have no idea why the satellites see the 15 micron fundamental bend and rotational sidekicks radiating at 217K. This temperature is remarkably similar from the Sahara to the Tropical Pacific and with MODTRAN at 600ppm.
This fixation is all the more surprising, as you point out, since the satellites are looking down through lots of reputed radiative cooling in the stratosphere and above.
You can see from this plot against line by line radiation (Clough 1995) that the satellites are seeing CO2 radiating at about the altitude of maximum ozone. A decent hypothesis might be that ozone absorption is kinetically lighting up CO2.
One thing for sure, the satellites are not seeing photons from the surface. CO2 absorbs 98% of surface radiation in these bands in the first meter. The atmosphere radiates as a blackbody up to about one kilometer. Above that CO2 goes its own way and radiates colder than the Planck temperature.
I do not know all the details, in which way the LW radiation behaves in the atmosphere. I keep the following things as facts: 1) The GH phenomenon happens in the troposphere 98 %, 2) The OLR at TOA is about 239 W/2 and it includes a radiation flux called transmittance flux. This flux is 83 W/m2 in the clear sky conditions ( in the cloudy sky conditions every photon will be absorbed). The transmitted flux passes the atmosphere in the clear sky conditions without absorption. This means that a photon emitted from the surface can be detected in the space.
This is the same phenomenon that the SW solar irradiation passes through the atmosphere: the original flux is 342 W/2, 104 W/m2 is reflected, 71 W/m2 is absorbed by the atmosphere, and 168 W/m2 is absorbed by the surface. The photons from the Sun passes through the atmosphere and these photons create the flux of 168 W/m2.
For me the question what happens above the troposphere is “nice to know”, but it has almost no role in the climate change, because the absorption is the key and it happens in the troposphere.
The stratosphere is also the “planet”. The effects are three dimensional. A vertical (or oblique) gradient is more powerful than a horizontal gradient because it engages the lapse rate for additional potential energy.
While, as you say, the CO2 and water absorption happens in the troposphere, the ozone absorption happens both in the stratosphere and near the surface. Ozone is a very significant absorbing gas in both the UV and IR spectra.
The surface emitted IR radiation is allowed to escape to space in the “atmospheric window”, dirty as it is in the tropics, on either side of a significant bite from ozone. It is not clear whether this bite occurs at the surface or in the lower stratosphere.
What is clear is that the radiation to space from CO2 at the tropopause and above seen by satellites is NOT radiation from the surface. It is different energy. This is why your simplistic averaging does not work.
“The climate sensitivity” (TCS) should be called “the equilibrium climate sensitivity” (TECS). It is the ratio between the change in the spatial average of the surface air temperature at equilibrium and the change in the logarithm of the atmospheric CO2 concentration. The numerical value of about 3 Celsius per CO2 doubling that is assigned by the IPCC to TECS is scientific nonsense as the spatial average of the surface air temperature at equilibrium is insusceptible to being measured.
Thoughtful and intelligent comments by most bloggers. I recommend especially by Dr. Antero Ollila for detailed numbers. To look at long term average energy balance per sq. meter: Water vapor/clouds/ice crystals make up the majority of radiation to space (an absolute 2nd law requirement to balance solar input to earth), is on average a 160 watt cooling agent (there is no other material in the atmosphere to do it) by definition thus a component of negative feedback along with IR window (~40 watts) and CO2 itself (~20 watts). Doubling density of CO2 at higher, cooler radiation escape altitude computed by Harvard using HITRAN detracts max of 2 watts radiation of the CO2 spectrum, thus a positive feedback effect to doubling. This 2 watt accumulation by the earth and atmosphere would drive an increase in 0.5C temperature to balance the average radiation demanded by the 2nd law. Tho with continued $billions endless details can be found and argued for another 30 years, many of which may be correct but difficult to attribute in measurements, the earth will continue to balance the energy input by using its only tools described above.
A note: Unlike the sun and its CME, CO2 alone has no mechanism ie. power or cloud modification to change the energy input and cannot drive any change in water vaporization, a favorite conjecture of the positive feedback cohort. Even if it did, on balance water vapor is 2/3 of the radiant cooling and therefore also the strongest net negative feedback. (I hear an argument that GH warming of the air is a forcing function. But without an increase in power it can force nothing. An increase of 0.5 C in air temperature is a long term (100 yr) minor accumulation of energy in the atmosphere as the average air temperature rises and matches the average surface temperature. It is not an additional power source which can evaporate additional water. In fact its warming comes from increase surface temperature not the other way around.)
The IPCC’s “climate sensitivity” cannot be reproduced as it is the ratio of two numbers. The numerator is the change in the equilibrium surface air temperature but the equilibrium surface air temperature cannot be measured.