- JoNova - http://joannenova.com.au -

New Science 9: Error 3: All Radiation Imbalances Treated the Same — The Ground is not the sky!

Posted By David Evans On October 4, 2015 @ 7:56 pm In Global Warming | Comments Disabled

Climate Models, Model architecture, feedbacks, David Evans, Error


The ground is not the sky

Here’s a big big flaw that is easy for anyone to understand, yet has lain at the core of the climate models since at least 1984. Indeed, you’ll wonder why we all haven’t been chuckling at this simplistic caricature of our atmosphere for 31 years.

The theory underlying the alarm about CO2 is built around a bizarre idea that blocking outgoing energy in the CO2 pipe is equivalent to getting an increase in sunlight. The very architecture of all the mainstream climate models assumes that the Earth’s climate responds to all radiation imbalances or “forcings” as if they were all like extra sunlight. (We call that extra absorbed solar radiation (ASR) to be more precise. It’s all about the sunlight that makes it through to the surface.)

Extra sunlight adds heat directly to the Earth’s surface, and maybe the climate models have correctly estimated the feedbacks from clouds and evaporation and what-not to surface warming. But it is obvious, in a way even a child could comprehend, that this is not the same as blocking outgoing radiation in the upper atmosphere, which is the effect of increasing CO2. Why would the Earth’s climate respond to this in an identical way? Why would we think that evaporation, humidity, winds and clouds would all change in the same direction and by the same magnitude, whether the warming occurred by adding heat to the ground or by blocking heat from escaping to space from the upper atmosphere?

Climate Models, Model architecture, feedbacks, David Evans, circuit diagram

Computation diagrams like this expose the architecture of climate models much better than a bunch of equations.

The climate modelers have viewed Earth as a baby-simple energy-in energy-out diagram — but in reality, for starters, there is one path in, and four main paths out. Blocking the one solo path that energy comes in on is not the same as blocking one of the four exits, where energy escaping to space can reroute and flow out a different pipe.  This is not a symmetric or reversible flow. Also, the energy flowing out is at different wavelengths to the energy flowing in; they don’t have the same effect as they travel through the air.

In short, the ground is not the sky, yet conventional climate models treat warming on the ground as the same as blocking outgoing radiation in the sky — they say they have cause the same radiation imbalance, so they have the same “forcing”, so they have the same effect.

Establishment scientists have been touting this simplicity as a feature for years, e.g. right in the abstract of James Hansen’s landmark 1984 paper[1]

“Our 3-D global climate model yields a warming of 4°C  for either a 2 percent increase of [total solar irradiance] or doubled C02.”

And on page 138:

The patterns of temperature change are remarkably similar in the [total solar irradiance] and C02 experiments [i.e. the answers his models give him], suggesting that the climate response is to first order a function of the magnitude of the radiative forcing. The only major difference is in the temperature change as a function of altitude; increased C02 causes substantial stratospheric cooling [due to sunlight on the way in interacting with ozone]. This similarity suggests that, to first order, the climate effect due to several forcings including various tropospheric trace gases may be a simple function of the total forcing.

This is Hansen saying that experiments based on his computer models show extra sunlight and extra CO2 have the same effect (once the effect of incoming sunlight on ozone is stripped out). His models are based on the basic climate model, which treats all forcings the same. It’s circular all the way down.

This over-simplification is the inevitable result of an architecture based only on a simple radiation balance. There is more to the climate than balancing radiation!  Any radiation imbalance, no matter what the source, has the same effect in the conventional basic climate model, including all the feedbacks to the imbalance (and its very nearly the same in the GCMs; the differences are second order). If some climate phenomenon (such as the rerouting feedback of post 7) isn’t a response to sunlight then it does not — cannot — exist in the conventional basic climate model, and basically doesn’t exist in a GCM.

Because of this architecture, the models keep making predictions that don’t work. Modelers are so sure that this is “basic physics” and the models are right that they assume the equipment needs correction — but really it is the models that need rebuilding. What’s more likely, the models are right, or all the radiosondes, satellites, Argo buoys, and ground thermometers need adjustment in the same direction?

Years from now people will wonder how such a simple mistake could have diverted so many lives and so much money — Jo

 

9. Error 3: All Radiation Imbalances Treated the Same

Dr David Evans, 4 October 2015, David Evans’ Basic Climate Models Home, Intro, Previous, Next, Nomenclature.

We call the response of a climate model to increased absorbed solar radiation (ASR) its “solar response”. Due to its architecture, the conventional basic climate model applies its solar response to the radiation imbalance caused by any influence on climate, even a radiation imbalance due to increased CO2 — one size fits all. This causes clashes with certain physical realities, which we explore in this post with the dual aim of developing a more realistic model for estimating sensitivity to increased CO2.

While no model is perfectly realistic, these clashes are sufficiently severe as to make it difficult to take the conventional architecture seriously. This architecture, based only on a radiation balance,  is the foundation for both the basic climate model and the big computerized climate models (GCMs). Something more than a radiation balance is going to be required to more realistically model the effect of increased CO2.

Increased ASR primarily heats the surface, which could explain why the conventional model neglects feedbacks other than to surface warming (post 5), thereby excluding the possibility of a CO2-specific feedback such as the rerouting feedback (post 7). The conventional model considers only forcings (radiation imbalances due to influences on climate) and “feedbacks” (but only in response to surface warming), so it has a blindspot for feedbacks other than in response to surface warming. Due to the possibility of CO2-specific feedbacks that do not apply to increased ASR, climate model obviously needs a specific response to increased CO2. There is no place for a CO2 response distinct from the solar response in the conventional architecture, but there is in the alternative model developed later in the series.

Following the conventional architecture, the GCMs apply the solar response to all radiation balances to first order, where as we argue that the actual response to increasing CO2 is very different from the solar response.

Interchangeability

The conventional basic climate model treats climate influences that cause the same radiation imbalance as interchangeable. Consequently, increased CO2, which blocks some heat from escaping to space from the upper atmosphere, is treated the same as increased sunlight, which warms the surface. The basic model is structurally unable to distinguish them, applying the solar response (how the Earth responds to absorbed sunlight) to both. Physically, this is rather implausible.

Technically (see Fig. 2 of post 3), the conventional model computes the radiation imbalance ΔI, then from that calculates the no-feedbacks surface warming λ0ΔI, then from that the with-feedbacks warming

All of the information about the influence of the climate drivers is therefore encapsulated in the radiation imbalance ΔI; the model is blind to anything about the drivers that is not in ΔI.

The various climate drivers are thus all interchangeable (or “fungible”) — the influences of any two drivers that cause the same radiation imbalance (i.e. have the same forcing) are treated identically in the conventional model. Interchangeability is an inevitable consequence of the radiation balance architecture (Fig. 2 of post 3, Fig. 1 of post 5).

The conventional model is structurally unable to distinguish warming due to extra sunlight from warming due to extra CO2: same forcing, same contribution to the radiation imbalance, so same surface warming and same feedbacks. But these drivers are quite different: extra sunlight directs more input energy to the surface and changes the outgoing longwave radiation (OLR), whereas extra CO2 impedes energy radiation to space from the higher atmosphere and does not change OLR (by energy balance, because CO2 does not affect the amount of absorbed sunlight, ignoring the minor effect of albedo feedbacks in response to surface warming).

The feedbacks in the conventional model only respond to surface warming, so the feedbacks to extra sunlight and extra CO2 are identical in the conventional model — they drive identical changes in average height of the water vapor emission layer (WVEL) and cloud tops, changes in average lapse rate, etc. Given the physical differences involved, this seems implausible.

The concept of forcing relies on interchangeability to be useful. The semantics of the word “forcing” obscures important differences: while increased CO2 is obviously a “forcing”, in that it forces the climate to change ad creates a radiation imbalance, it is not the same type of “forcing” as increased sunlight — for instance, the latter changes OLR when steady state resumes, while the former does not (except in a minor way through albedo feedbacks).

Only CO2 enrichment triggers the rerouting feedback, further illustrating why the influence of extra CO2 is not interchangeable with extra sunlight.

Solar Response Applied to the CO2 Influence

In the conventional basic climate model all forcings are interchangeable, so they are all equivalent to increased absorbed sunlight (ASR). The model then applies its solar response to those forcings. Crucially, increased ASR is the one forcing whose effects on OLR, before feedbacks, we can be relatively certain of — via the Stefan-Boltzmann law.

The conventional model expresses the Stefan-Boltzmann law through the Planck feedback, which is the increase in OLR per unit of surface warming under the Planck conditions — namely that all else besides tropospheric temperature and OLR are held constant, there are no feedbacks, all tropospheric temperatures move uniformly, and stratospheric temperatures are unchanged (Soden & Held, 2006, pp. 3355-56[2]). The Planck conditions are motivated by the problematic use of partial derivatives in the conventional model — see post 2 and post 4.

Let us instead explore the solar response and the Stefan-Boltzmann law without partial derivatives and the Planck conditions, by instead using the radiating temperature TR and the Stefan-Boltzmann sensitivity (SBS), defined in post 8. The SBS applies to the Earth under all circumstances — unlike the Planck sensitivity, which is only applicable under the hypothetical Planck conditions.

The Stefan-Boltzmann law involves the OLR R and the radiating temperature TR. To find the increases in these quantities in the conventional model, we perform two rearrangements of Fig. 2 of post 3 — the first makes ΔR explicit, and the second reveals ΔTR. These re-arrangements also suggest how to develop a better model.

- First Rearrangement

The increase in OLR, ΔR, is equal to the increase in ASR, ΔA (by Eq. (1) of post 2), which in turn is the sum of the increase in no-feedbacks ASR, ΔANF, and the increase in ASR due to feedbacks in response to surface warming. So let us partition the feedbacks in response to surface warming into those that affect albedo, denoted by fα (all the “surface albedo” feedback and some of the “cloud” feedback in AR5), and those that do not, denoted by fα:

(For the feedback values in AR5, see Eq. (10) in post 3. However AR5 does not give the breakdown of the cloud feedback into shortwave effects, which affect albedo, and longwave effects, which do not. For those values we averaged the sources referenced by AR5, which break them down by SW and LW. Cloud feedbacks are notoriously the largest source of uncertainty in the solar response; hence the large uncertainties.)

Then Fig. 2 of post 3 becomes Fig. 1 here:

Conventional basic climate model, rearranged to show ASR

Figure 1: Conventional basic climate model, re-arranged to explicitly show the increase in ASR and thus in OLR. As per Fig. 2 of post 3 except feedbacks in response to surface warming are partitioned by whether or not they affect albedo.

 

(To compute the surface warming in Fig. 1, first apply Fig. 1 of post 3 with a equal to λ0 and b to fα to form the multiplier

then move the output of the albedo feedbacks to between the output of the purple adder and the Planck sensitivity, then re-apply Fig. 1 of post 3 with a equal to this multiplier and b to fα:

This agrees with Eq. (16) of post 3, so Fig. 2 of post 3 and Fig. 1 here are identical for computing surface warming.)

- Second Rearrangement

To reveal the increase in radiating temperature ΔTR, two changes are needed. First, we use the Stefan-Boltzmann sensitivity (SBS) λSB in place of the Planck sensitivity λ0, because (i) we are interested in ΔTR but λ0 involves ΔTS while λSB involves ΔTR, and (ii) λ0 only applies under the Planck conditions. So we define the sensitivity ratio as

and replace λ0 by ηλSB.

Second, by its definition in Eq. (5) of post 8, multiplication by the SBS only produces ΔTR when  it multiplies ΔR. So we convert the non-albedo feedbacks into an equivalent open-loop multiplier e, so that they won’t add to the input as they do in Fig. 1. Applying the feedback loop diagram in Fig. 1 of post 3 to the loop consisting of the non-albedo-feedbacks and the Planck-sensitivity in Fig. 1, we set

Then Fig. 1 becomes Fig. 2:

Conventional basic climate model, re-arranged to show OLR input to Stefan-Boltzmann sensitivity.

Figure 2: Conventional basic climate model, re-arranged to explicitly show the OLR input to the Stefan-Boltzmann sensitivity.

 

(To compute the surface warming in Fig. 2, move the output of the albedo feedbacks to between the output of the purple adder and the SBS, then apply Fig. 1 of post 3 with a equal to λSBηe and b equal to fα:

This agrees with Eq. (16) of post 3 and Eq. (4) of this post, so Fig. 2 of post 3, Fig. 1 here, and Fig. 2 here are all identical for computing surface warming and ECS.)

- Remarks

The Stefan-Boltzmann law relates R to TR, and its slope, the SBS, relates ΔR to ΔTR. The Stefan-Boltzmann law, when applied to Earth, only says anything about R, ΔR, TR, and ΔTR; it says nothing about other amounts of radiation or other temperatures.

For a move between two steady states, the increase in ASR ΔA is equal to the increase in OLR ΔR, which the SBS converts to the increase in radiating temperature ΔTR, which in turn depends on the temperatures of the physical emission layers that emit OLR to space. Thus the SBS relates the response of temperatures on Earth to the energy coming in from the Sun; it describes the solar response of the Earth, before feedbacks.

In the conventional model, the influence of extra CO2 is fed into the SBS (purple adder, Fig. 2). If there is only a CO2 influence — no solar influence and no influence from the drivers marked “other” — the radiation imbalance ΔI  is DR,2XΔL, which is input into the SBS along with the albedo feedback fαΔTS.

Now, finally, we come to the nub of the matter.

Fig. 2 demonstrates that the conventional basic climate model applies the solar response to the influence of CO2. More, it applies the solar response to all climate influences — one size fits all.

While it is the inevitable result of the radiation-balance architecture, how realistic can it be to apply the Earth’s solar response, its response to an increase in absorbed sunlight, to an increase in the amount of OLR blocked by a greenhouse gas? The former adds heat directly to the surface; the latter blocks some heat from escaping to space from the upper atmosphere. The former increases OLR; the latter leaves OLR constant (neglecting minor changes due to surface albedo feedbacks).

Shouldn’t a response specific to the greenhouse gas be applied instead? Applying the solar response to non-solar influences, seems to be inviting problems — yet the conventional model allows only the solar response to any influence.

The SBS, which is only about changes in OLR, is being applied to the influence of the extra CO2. Although it makes sense within the context of the radiation-balance architecture, this is unrealistic modeling.

Notice that if the input to the SBS was only the solar influence, ΔA, then the output of the SBS would be the radiating temperature. Only under this condition does the SBS relate the increase in OLR to the increase in radiating temperature, which is the only thing it is qualified to do by the Stefan-Boltzmann law. This tells us how to improve the model — do not feed the non-solar influences into the SBS.

That the conventional model necessarily applies a specifically solar response to the influence of extra CO2 may have tended to be overlooked because the usual view of the conventional model (Fig. 2 of post 3) obscures the increases in OLR and radiating temperature, while entangling the albedo and non-albedo feedbacks.

 

References

[1^] Hansen J., A. Lacis, D. Rind, G. Russell, P. Stone, I. Fung, R. Ruedy and J. Lerner, (1984) Climate sensitivity: Analysis of feedback mechanisms. In Climate Processes and Climate Sensitivity, AGU Geophysical Monograph 29, Maurice Ewing Vol. 5. J.E. Hansen and T. Takahashi, Eds. American Geophysical Union, pp. 130-163 [Abstract]

[2^] Soden, B. J., & Held, I. M. (2006). An assessment of climate feedbacks in coupled ocean-atmosphere models. J.Clim., 19, 3354-3360.

VN:F [1.9.22_1171]
Rating: 8.9/10 (91 votes cast)

Article printed from JoNova: http://joannenova.com.au

URL to article: http://joannenova.com.au/2015/10/new-science-9-error-3-all-radiation-imbalances-treated-the-same-the-ground-is-not-the-sky/

Copyright © 2008 JoNova. All rights reserved.