Trick of the radiative forcing of 3.7W/m2 at the tropopause
by Kyoji Kimoto
Radiative forcing is defined as 3.7W/m2 for 2xCO2 at the tropopause by the IPCC Third Assessment Report (2001) to avoid the usage of the surface radiative forcing of around 1W/m2. It is greatly reduced from the radiative forcing of around 4W/m2 at the tropopause due to IR absorption overlap between CO2 and water vapor plentifully existing at the surface.
Kiehl & Ramanathan (1982) developed a basic idea of the IPCC trick to overcome Newell & Dopplick (1979) claiming a climate sensitivity of 0.24K with the surface radiative forcing of around 1 W/m2 as shown by the following history of the AGW theory.
1959: Plass wrote:
In addition, nearly all water vapor remains close to the ground, while carbon dioxide diffuses more evenly through the atmosphere. Thus throughout most of the atmosphere carbon dioxide is the main factor determining changes in the radiation flux.
Wiscombe (2013) explains the Plass’s idea as follows in his lecture at NASA.
Plass also notes that CO2 greenhouse action is relatively unimpeded above 2-3km.
1967: Manabe & Wetherald obtained a climate sensitivity of 2.4K with one dimensional radiative-convective model (1DRCM) utilizing the fixed lapse rate assumption of 6.5K/km for 1xCO2 and 2xCO2 giving uniform warming throughout the troposphere and the surface. They did not mention the Plass’s idea that CO2 greenhouse effect is greatly reduced at the surface due to IR absorption overlap with water vapor because their careless assumption of the fixed lapse rate prevented their study from self-criticism of uniform warming (see Fig.2).
1975: Manabe & Wetherald obtained an averaged climate sensitivity of 2.9K and polar climate sensitivity of 7-9K with 3DGCM which is based on the 1DRCM study of Manabe & Wetherald (1967).
1979: Newell & Dopplick obtained a climate sensitivity of 0.24K with the surface radiative forcing of around 1 W/m2 to criticize Manabe & Wetherald (1975).
1979: Ramanathan et al. wrote:
For example, with a doubling of CO2, Manabe & Wetherald (1975) estimates an increase in surface temperature of 2.0-2.5K within equatorial regions. From Fig.5 the surface heating of 1.1 W/m2 at the equator, due to the radiative effects of doubled CO2, can cause a maximum surface warming of about 0.2K, and hence roughly 90% of the 2.0-2.5K surface warming obtained by Manabe & Wetherald (1975) is caused by the atmospheric feedback processes described above.
1981: Ramanathan obtained the following surface warming with the feedback mechanism shown by Fig.1 copied from his review in 1998.
1981: Hansen et al. showed a climate sensitivity of 1.9K with 1DRCM study following Manabe & Wetherald (1967) utilizing the radiative forcing of 4 W/m2.
1982: Kiehl & Ramanathan obtained the following results for 2xCO2 utilizing H2O continuum absorption in the 12-18 microns region.
But, the influence of this H2O overlap with CO2 bands is relatively smaller on the radiative heating of the joint surface/troposphere system. In particular, the effect of CO2 increase on the radiative heating of the joint surface/ troposphere system is affected very little by the presence of the water vapor continuum in the 12-18 microns region. We stress the importance of considering the troposphere/ surface system as a whole, when analyzing the effects of increasing CO2. As pointed out recently by Ramanathan (1981), results based upon surface energy balance alone can lead to incongruous conclusions.”
From Hansen et al. (1981) and Kiehl & Ramanathan (1982), the radiative forcing for
2xCO2 is 4 W/m2 at the tropopause giving the no-feedback climate sensitivity of 1.2K with the sensitivity factor of 0.3K/(W/m2) based on Cess (1976) as follows:
4 W/m2 x 0.3 K/(W/m2) = 1.2K
Soden & Held (2006) shows climate sensitivity is 3K for 2xCO2 from the 14 GCM studies for the IPCC 4th Assessment Report (2007) as follows:
Climate sensitivity = no-feedback sensitivity (Planck response) x feedbacks
= 1.2K x 2.5 = 3K
Here, feedbacks are water vapor, ice albedo, lapse rate and cloud feedback.
The no-feedback sensitivity is uniform warming throughout the troposphere and the surface, which is originated from the 1DRCM studies of Manabe & Wetherald (1967) and Hansen et al. (1981) utilizing the fixed lapse rate assumption of 6.5K/km for 1xCO2 and 2xCO2.
The 1DRCM studies, however, are fudged due to their strong dependence on lapse rate used according to Hansen’s idea expressed in an interview with Spencer Weart held on 23 October, 2000 at NASA here.
And Cess admits his mathematical errors of the derivation to obtain the sensitivity factor of 0.3 K/(W/m2) in Cess (1976) here and here.
Kiehl & Ramanathan (1982) is based on the joint surface/troposphere system which is originated from Cess (1976) and is in line with the 1DRCM studies giving uniform warming throughout the troposphere and the surface due to the fixed lapse rate assumption of 6.5K/km for 1xCO2 and 2xCO2. Since it is a blanket model, the OLR decrease at the tropopause heats the troposphere and the surface as shown by their conclusion above.
On the contrary, a radiation height change model is the orthodox AGW theory as shown by Mitchell (1989) and Held & Soden (2000). In Fig.2, radiation height increases from point a to point b due to increased opaqueness when CO2 is doubled. This decreases the temperature at the effective radiation height of 5km causing an energy imbalance between the absorbed solar radiation (ASR) of 240W/m2 and the outgoing long wave radiation (OLR) in Fig. 3.
In order to restore the balance of energy, the radiation temperature increases from point b to point c. Based on the Stefan-Boltzmann law, a warming of 1K at the effective radiation height is enough to remove the energy imbalance caused by the radiative forcing of 4 W/m2 for 2xCO2 in Fig. 2.
For the Manabe method, the surface temperature increases in the same degree of 1K utilizing the fixed lapse rate assumption of 6.5K/km in Fig. 2. It, however, is erroneous since the 1DRCM studies are fudged according to the Hansen’s idea above.
In contrast, Kimoto model follows Ramanathan (1981) giving the no-feedback sensitivity of 0.17K with the direct heating of 1.2W/m2 for 2xCO2 from the Stefan-Boltzmann law at the surface. It is also in line with Newell & Dopplick (1979) giving a surface climate sensitivity of 0.24K based on the surface radiative forcing of around 1W/m2 and the evaporation cooling from the surface of the ocean.
In conclusion, the surface warming should be calculated with the surface radiative forcing of around 1 W/m2 utilizing the Stefan-Boltzmann law at the surface. The upper troposphere warming nullifies the radiative forcing at the tropopause due to CO2 increase with restoring OLR which is decreased by the opaqueness increase of the atmosphere.
Fig. 2 Comparison between Manabe method and Kimoto model.
Fig. 3 Energy budget of the earth adapted from Dorland (2006).
– Cess, R.D., An appraisal of atmospheric feedback mechanisms employing zonal climatology, J. Atmospheric Sciences, 1976, 33, 1831-1843.
– Hansen, J., Johnson, D., Lacis, A., Lebedeff, S., Lee, P., Rind, D. and Russell, G., Climate impact of increasing atmospheric carbon dioxide, Science 1981, 213, 957-966.
– Held, I.M. and Soden, B.J., Water vapor feedback and global warming, Annu. Rev. Energy Environ., 2000, 25, 441-475.
– Kiehl, J.T. and Ramanathan, V., Radiative heating due to increased CO2: The role of H2O continuum absorption in the 12-18 micron region, J. Atmospheric Sciences, 1982, 39, 2923-2926.
– Manabe, S. and Wetherald, R.T., Thermal equilibrium of the atmosphere with a given distribution of relative humidity, J. Atmospheric Sciences, 1967, 24, 241-259.
– Manabe, S. and Wetherald, R.T., The effects of doubling theCO2 concentration on the climate of a general circulation model. J. Atmospheric Sciences, 1975, 32, 3-15.
– Mitchell, J.F.B., The greenhouse effect and climate change. Reviews of Geophysics, 1989, 27, 115-139.
– Newell, R.E. and Dopplick, T.G., Questions concerning the possible influence of anthropogenic CO2 on atmospheric temperature, J. Applied Meteorology, 1979, 18, 822-825.
– Ramanathan, V., Lian, M.S. and Cess, R.D., Increased atmospheric CO2 Zonal and seasonal estimation of the effect on the radiation energy balance and surface temperature. J. Geophysical Research, 1979, 84, 4949-4958.
– Ramanathan, V., The role of ocean-atmosphere interactions in the CO2 climate problem, J. Atmospheric Sciences, 1981, 38, 918-930.
– Soden, B.J. and Held, I.M., An assessment of climate feedbacks in coupled ocean-atmosphere models. J. Climate, 2006, 19, 3354-3360.
22 responses to “Japanese Scientist Explains “Trick” Behind 3.7 Watts Per Square Meter Forcing At The Tropopause”
Kimoto is wrong about the no feedback response. Period. Monckton derived it (1.16C) quite clearly in his third ‘Feet of Clay’ post at WUWT. Lindzen simplifies to 1.2C in his 2011 feedback paper, and in his House of Commons Talk in 2012.
Doen’t help to share around scientific sounding nonsense. Discredits skeptics.
To say that someone is “wrong” about non-real-world, theoretical/hypothetical phenomena because there are others who have come to the conclusion it is 1.16C or 1.2C (actually Lindzen and Choi  put no feedback response at “about 1 C”, not 1.2 C) is a tad bit presumptive. It assumes there is such a thing as a “wrong” or “right” answer to the question of what might happen to the temperature of the Earth’s system due to a change of 3/100ths of a percentage point of one single variable’s atmospheric concentration (0.03% to 0.06%), as this assumes that all other variables affecting climate can and do remain constant and have had and continue to have little to no effect on the climate system. And that’s quite an outrageously simplistic presumption.
More agnostic and uncertain language is in order when speaking of such a theoretical understanding of what the temperature of the Earth will be 150 years from now.
For instance, has someone been able to establish that this “laws of physics” model is “wrong” that says doubled CO2 yields a “0.01–0.03 °C” temperature increase? If so, where is that proof?
Florides and Christodoulides, 2009
“A very recent development on the greenhouse phenomenon is a validated adiabatic model, based on laws of physics, forecasting a maximum temperature-increase of 0.01–0.03 °C for a value doubling the present concentration of atmospheric CO2. Moreover, data from palaeoclimatology show that the CO2-content in the atmosphere is at a minimum in this geological aeon. Finally it is stressed that the understanding of the functioning of Earth’s complex climate system (especially for water, solar radiation and so forth) is still poor and, hence, scientific knowledge is not at a level to give definite and precise answers for the causes of global warming.”
Kennith, when someone is wrong, they are just wrong. Period. There is in science an about right and an about wrong. The proof of about no feedbacks ~1.1-1,2 lies in the various radiative transfer codes, experimentally verified based on lab physics. They hew to accepted and experimentally verified physics. Deny that, you deny the basic scientific method.
I shall repeat. You do skeptics no good by challenging well proven physics, while completely missing the weak points of CAGW. Learn. Improve.
Now, on natural variation and feedbacks, I completely agree we dunno. See many posts and writings elsewhere. But that is not what you wrongly argued above.
“To say that someone is “wrong” about non-real-world, theoretical/hypothetical phenomena because there are others who have come to the conclusion it is 1.16C or 1.2C (actually Lindzen and Choi  put no feedback response at “about 1 C”, not 1.2 C) is a tad bit presumptive. It assumes there is such a thing as a “wrong” or “right” answer to the question of what might happen to the temperature of the Earth’s system due to a change of 3/100ths of a percentage point of one single variable’s atmospheric concentration”
That is called “science”. I am really shocked by such absurd claims!
Huge parts of our every day life depend on scientists making these sort of assessments and that it is theoretical is simply a fact in many aspects of science.
Sorry sod, but theoretical models are not reality. To even form a hypothesis, there must be observational evidence. And yet there is no observational evidence available that shows increasing or decreasing CO2 concentrations by 0.000001 (1 ppm) are the cause heat changes in the global oceans to depths of 1000s of meters. And CO2-heats-water *necessarily* has to be established (and physical measurements must be provided) before presuming that CO2 heats the air for 2 X CO2 temperature values, as the heat capacity of the oceans is 1,000 times greater than the air (i.e., the oceans heat the air, not the other way around).
So if you think the 2 X CO2 = 1.2 C conceptualization is *not* a theoretical/hypothetical model, but actual scientific reality, you’re going to need to provide physical measurements from a scientific experiment that establishes that CO2 changes cause OHC changes, as well as provide the physical measurements supporting this. Since such a scientific experiment doesn’t exist, you cannot claim that the 2 X CO2 = 1.2 C conceptualization is *not* a theoretical/hypothetical model.. Because that truly is all that it is.
This is basically the same point that Miskolczi — i.e., the lack of optical depth — has made. It supports the gravito-thermal greenhouse theory quite well.
And that sky dragon theory has been thoroughly discredited. The fatal physics flaw is in the false definition of thermodynamic work.
Please stop espousing such garbage. It discredits skeptics, and gives ‘science is settled, all else is Flat Earth’ an undeserved bad name. Educate yourself. Please.
And then there are other scientists who do not agree that his work has been “thoroughly discredited”.
Recently Dr. Miskolczi’s greenhouse theory is the only existing valid theory which can predict and explain a-priori the observed infrared characteristics of the Earth’s atmosphere, the global average water vapor content of the atmosphere, and the greenhouse effect.
Anyone wishing to refute the validity of MGT [Miskolczi Greenhouse Theory] will have to perform these scientific tasks:
1 – Present quantitative results based on global scale radiosonde observations resulting in a DIFFERENT
infrared optical thickness.
2 – Present quantitative results showing that the long term global average A τ is NOT a constant.
3 – Present PROOFS against his theoretical equations.
So far no criticism from scientists who have the resources to reproduce the numerical results and empirical facts on which the MGT rests has appeared. Scientists at NASA, JPL, AERI, OSU, CSU, and NCAR have not spoken. Those who really understand what the MGT is and what are its consequences have chosen to be silent.
Miskolski is as mathematically wrong as Kimoto. That has been shown more than once. Don’t support junk science on any side. Period. If you cannot work out the science for yourself, remain silent on the sidelines. Lest younotherwise damage skeptics who know what they are talking about.
“skeptics who know what they are talking about”
So you *know* what you are talking about, and you *know* what the no feedback temperature of the Earth will be upon reaching 600 ppm….
Lindzen says it’s “about 1°C” for the no feedback temperature value. Is he mathematically “wrong” by 0.16 or 0.2°C? Can you provide some proof that he’s wrong and that you are right about that extra 0.16 to 0.2°C of temperature change upon reaching 600 ppm? For that matter, can you provide proof that Florides and Christodoulides (2009) are “wrong” with the “laws of physics” model they use to derive a CO2-driven temperature value of 0.02°C upon reaching 600 ppm?
Or will you acknowledge this is all just one theoretical opinion against another theoretical opinion about a phenomenon that cannot even be subjected to observational tests in the real world—especially since it hasn’t even been *observed* in a scientific experiment that CO2 concentration changes can and do have a measurable effect on ocean heat changes, since its the oceans that heat the atmosphere, not the other way around?
Why so much certainty, Mr. Istvan?
“However, warming from a doubling of CO2 would only be about 1°C (based on simple calculations where the
radiation altitude and the Planck temperature depend on wavelength in accordance with the attenuation coefficients of well-mixed CO2 molecules; a doubling of any concentration in ppmv produces the same warming because of the logarithmic dependence of CO2’s absorption on the amount of CO2)” — Lindzen and Choi, 2011
Rud Istvan 22. October 2016 at 2:13 AM | Permalink | Reply
“Miskolski is as mathematically wrong as Kimoto. That has been shown more than once.”
I have never seen a refutation of Miskolski. You have obviously seen several of them. Please provide links.
“Kennith, when someone is wrong, they are just wrong. Period. There is in science an about right and an about wrong.”
Correct. And that particular brand of science is rooted in *observational* evidence, not theoreticals and hypotheticals as the 1.2°C no-feedback model is. We do not have observational evidence confirming that doubling CO2 concentrations *actually* have caused or will cause a ___°C temperature change in the global climate system once it reaches a certain threshold of ppmv concentration. This is entirely an *assumption* based upon hypotheses and theories.
We don’t even have observational evidence that confirms that varying CO2 concentrations up or down in volumes of parts per million over ocean waters is capable of even *affecting* the heat content of the ocean (0-4000m), let alone acting as the *dominant* means by which the OHC will change and thus induce atmospheric warming. Because of the heat capacity of the ocean is >1,000 times greater than the heat capacity of the air, the CO2 concentration change hypothesized to cause 1.2°C of an air temperature change once it reaches 600 ppm necessarily has to first be capable of heating up the ocean to accomplish this feat. And, of course, we have no observational evidence or physical measurements confirming that CO2 is capable of changing ocean heat content, and if so, by how much. Given this context, can you understand why your statements of certainty (in essence, this temperature value is right, that one is wrong) presumptuously concludes that we already have confirmed to what extent (physical measurements) CO2 concentration changes affect OHC changes — when no such confirmation has existed?
True skeptics don’t write using such *certain*, right-and-wrong language when the uncertainty in these *guesses* about what the temperature of the Earth will be 100-some years from now is immense.
Can you answer this question: What are the *observed* physical measurements (in joules) for the amount of change in ocean heat content in the 0-2000 m layer for an increase of +10 ppm CO2? For a decrease of -10 ppm CO2? If so, please provide a source verifying these physical measurements associated with CO2 concentration changes for the 0-2000 m layer.
“The proof of about no feedbacks ~1.1-1,2 lies in the various radiative transfer codes, experimentally verified based on lab physics.”
Yes, Rud, and the “various radiative transfer codes” are entirely theoretical and not based on real-world observations. Again, the uncertainty is immense due to the extreme lack of observational evidence. It’s (the uncertainty) 10 times larger than the presumed forcing itself attributed to doubled CO2 (3.7 W m-2) itself. Even the IPCC agrees.
“Unfortunately, the total surface heat and water fluxes are not well observed. Normally, they are inferred from observations of other fields, such as surface temperature and winds. Consequently, the uncertainty in the observational estimate is large – of the order of tens of watts per square metre for the heat flux, even in the zonal mean.” — IPCC AR4
“The overall uncertainty of the annually averaged global ocean mean for each term is expected to be in the range 10 to 20%. In the case of the latent heat flux term, this corresponds to an uncertainty of up to 20 W m–2. In comparison, changes in global mean values of individual heat flux components expected as a result of anthropogenic climate change since 1900 are at the level of <2 W m–2 (Pierce et al., 2006)" IPCC AR5
Again, let's be careful with our language here. Skeptics are openly agnostic first. We shouldn't be going around characterizing one hypothetical model as right, and another as wrong, without acknowledging the inherent uncertainties —and that we do not have sufficient observational evidence to jump to conclusions. That's all I'm pointing out here. Is your hypothetical model "right"? In your mind, of course it is. That doesn't make your hypothetical model the "truth". Skeptics don't talk that way.
RI: “You do skeptics no good by challenging well proven physics”
Please provide the experimental/observational scientific evidence and physical measurements that have verifiably proved that raising CO2 concentrations up or down in volumes of parts per million over a body of water have changed the heat content of that body of water — and by how much. What scientific experiment has proved the “well proven physics” of 0.000001 (1 ppm) CO2 changes directly causing deep OHC changes?
Even RealClimate and SkepticalScience have acknowledged that we don’t even have experimental evidence of CO2 changes affecting OHC, so we have to use proxies (clouds). So if we have no real-world experimental evidence that CO2 changes cause OHC changes (and if so, what the physical measurements are), how can this be “well proven physics” in the mind of someone claiming to be skeptical?
RealClimate: “Clearly it is not possible to alter the concentration of greenhouse gases in a controlled experiment at sea to study the response of the skin-layer.”
SkepticalScience: “Obviously it’s not possible to manipulate the concentration of CO2 in the air in order to carry out real world experiments, but natural changes in cloud cover provide an opportunity to test the principle.”
“Trick of the radiative forcing of 3.7W/m2 at the tropopause”
3.7w/m2 radiative forcing is not how the CO2 doubling works in the atmosphere, but it is how it is implemented in climate models -> which explains the difference between reality and climate models.
This is basically the reason why there is no hot-spot in the troposphere in reality, whilst it appears in climate models.
Climate models cannot model properly the lapse rate -> the heat transfer in the atmosphere.
Without a proper energy transfer mechanism, models can be used for short term forecasting -> ie weather, but are wrong tools for long term forecasting -> climate, as these errors accumulate over time.
Correct. The presumption that theoretical models = reality (i.e., “proven physics”) is the fatal flaw of the analysis here.
Models can only be an approximation, they are not reality. To make the models better reflect reality basic research still is required.
Two things strike me as lacking —
1. That we understand how water behaves — no we don’t!
2. That how clouds behave is a known quantity — no it is not.
To anyone that thinks otherwise please explain, giving observed evidence, of what are the dynamic exchanges water vapor/gas undergo in the atmosphere at the edge of the troposphere (at around -45°C.)
Here are two starters for you —
Pure water forms a solid at -45°C but it is *not* ordinary ice. http://polymer.bu.edu/hes/articles/sbchmsss99.pdf (408kb PDF file)
and some observations…
I believe that if a little more effort was put into understanding water and clouds better then our understanding of both weather and climate would improve.
I’ll safely assume that my comment has hit the spam folder or moderation.
I’m just guessing here as there is never any conformation message to say the comment has gone anywhere.
The basic problem is that we do not know or understand how water works at the fundamental level.
Yes, strange things happen with clouds at the top of the troposphere as this old document testifies 10.1175/1520-0469(1981)0382.0.CO;2
And -45°C is a strange temperature for water. Just happens to be at the top of the troposphere.
DOI: 10.1175/1520-0469(1981)0382.0.CO;2 is a document from 1981 about clouds.
Strange things happen to water at -45°C. See http://news.mit.edu/2011/heavy-water-0801
What happened to comment #comment-1141049 and #comment-1140987
Pierre, I presume you did not approve?
Kimoto is wrong about the no feedback response. Period. Monckton derived it (1.16C) quite clearly in his third ‘Feet of Clay’ post at WUWT. Lindzen simplifies to 1.2C in his 2011 feedback paper, and in his House of Commons Talk in 2012.
Doen’t help to share around scientific sounding nonsense. Discredits skeptics…