Greenhouse Effect from "Radiative Forcing"

The Basic Postulate of CO2 alarmism is a no-feedback climate sensitivity of 1 C as global warming from doubling atmospheric CO2 according to Stefan-Boltzmann's radiation law in the form

dQ = 4 dT with dQ = 4 W/m2 the estimated "radiative forcing" from doubled CO2.

The Basic Postulate is the pillar of IPCC alarmism and has also been accepted as a valid starting point by leading skeptics such as Lindzen, Singer, Spencer and Lord M. From this common no-feedback sensitivity of 1C the debate between alarmists and skeptics then concerns whether feedbacks are positive increasing 1 C to alarming 3 C by IPCC, or negative decreasing 1 C to 0.5 C

by Lindzen et al.

The result is a never-ending debate about feedbacks, positive or negative.

But there is another approach, which I advocate and makes me into a denier in the eyes of my fellow skeptics, namely to question the Basic Postulate with its "radiative forcing".

What is then wrong with the Basic Postulate? Two basic things:

1. It is based on a extremely simplistic model as the simple algebraic model dQ = 4 dT of a very complex climate system.
2. It assumes that the climate system is driven by radiation rather than thermodynamics of winds, vertical convection, gravitation, rotation and evaporation/condensation.

The Basic Postulate thus puts radiation in the drivers seat and uses a extremely simplistic model to let "radiative forcing" drive temperature as a starting point. The focus is then cleverly shifted to the question of how to stop a supertanker already in motion, which is not easy to answer.

The Basic Postulate has been invented by IPCC to drive CO2 alarmism, but if this is not your goal then there is no scientific reason to adopt the Basic Postulate.

If you you don't accept the Basic Postulate then you have to start from scratch without any preconceived idea of what drives the climate system. And then it is not even clear that a bit more CO2 will cause warming. The only thing which is clear is that there is no scientific evidence indicating that it can have any observable effect.

I have asked the leading skeptics including Lindzen et al, why they all cling to the Basic Postulate, which lacks scientific rationale, and thus give IPCC a free ticket to sell CO2 alarmism.

The only answers I get is silence or ridicule. Reasonable?

Note the clever use of the term "radiative forcing":

• Can you question that the Earth + atmosphere is subject to "radiative forcing" from the Sun? No, this would be unreasonable.
• Can you question that the transfer of heat energy from the Earth surface to the top of the atmosphere is driven by "radiative forcing"? Yes, this is reasonable to do.

Note that Lindzen's greenhouse effect from 1997 is driven by a terrible "radiative forcing" with an Earth surface temperature of + 80 C. Is this really reasonable Prof Lindzen? Isn't this a bizarre idea?

Who knows, Prof Lindzen does not descend to answer a simple question from a simple professor of simple applied mathematics in simple little country close to the Polar circle, where radiative heating is not the driver of society nor science except, possibly, during the short Midsummer.

Richard Lindzen's Greenhouse Effect 2

In the previous post we met a bizarre "greenhouse effect" presented by Richard Lindzen in 1997.

Maybe this presentation is now outdated, and so let us take a look at how Lindzen describes the "greenhouse effect" today in

• Reconsidering the Climate Change Act Global Warming: How to approach the science. (Climate Models and the Evidence?)
• Seminar at the House of Commons Committee Rooms Westminster, London 22nd February 2012.

Slide 43 presents Lindzen's central argument:

• Adding greenhouse gases to the atmosphere must elevate the average emission level, and because of the first point, the new emission level is colder than the original emission level.
• This reduces the outgoing infrared radiative flux, which no longer balances the net incoming solar radiation.
• Note that this mechanism leads to the simple result that doubling CO2 gives rise to warming of about 1C.

Lindzen here refers to the Basic Postulate of CO2 alarmism of a climate sensitivity of 1C resulting from an application of Stefan-Boltzmann's radiation Law in the form dQ = 4 dT with

dQ = 4 W/m2 of "radiative forcing" from doubling of CO2.

We see that Lindzen no longer puts forward his idea from 1997 of a surface temperature of + 80 C with radiation alone, but instead uncritically adopts the Basic Postulate of CO2 alarmism used by IPCC.

I have argued at length that the Basic Postulate should not be accepted as a starting point, because it is based on a way too simplistic model of the climate system as the simple algebraic

equation dQ = 4 dT setting dQ = 4 by a wild guess and obtaining a dT = 1 without scientific significance.

Richard Lindzen, Roy Spencer, Fred Singer and Lord Monckton all seem to confess to the Basic Postulate and thus give IPCC a free ticket to sell CO2 alarmism.

When I try to discuss the nature of the "greenhouse effect" and the scientific relevance of the Basic Postulate, I meet silence or ridicule from leading skeptics. Reasonable?

I have asked Prof Lindzen for a comment or clarification without any response.

Lindzen's Bizarre Greenhouse Effect

Richard Lindzen describes the greenhouse effect as follows (1997):

• The most important consequence of the convective heat transport is that the surface is much cooler (15 C) than it would be in pure radiative equilibrium (80 C).
• The surface is still receiving about 240 W/m2 from the Sun and even larger amount of backradiation from the atmosphere, but it is losing most of the energy by convection, not by radiation.
• The actual operation of the greenhouse effect is much more complicated and subtle than is usually recognized. However, excellent treatments have existed in the literature for many years.

OK, so Lindzen claims that the surface temperature would be + 80 C if not convection took it down to a livable + 15 C. Radiation is by Lindzen presented as a frightening monster which is somehow tamed by benevolent convection.

Lindzen views the discussion of the greenhouse effect requested by Pierre Latour and myself as being bizarre.

To me it is Lindzen's greenhouse effect which is bizarre.

What Is The "Greenhouse Effect"?

The Greenhouse Effect according to EPA

In recent posts I have documented a discussion with Roy Spencer and Fred Singer on "backradiation" and the "greenhouse effect" connecting to an exchange between Pierre Latour and Richard Lindzen with the following summary by Lindzen:

• This rather bizarre 'discourse' seems to centered on the fact that the greenhouse effect that you are criticizing is essentially the one presented by Gore and possibly implicit in the Trenberth-Kiehl figure. This is not the greenhouse effect that Roy, Fred and I are talking about. The one we are talking about is the one that is actually working in all radiative convective calculations and in GCMs. Why don't you spend the little time needed to understand the difference?

The rather bizarre discourse illustrates the fact that the meaning of the "greenhouse effect" has many different definitions:

1. What makes the Earth’s surface warmer than it would otherwise be (e.g. Spencer).
2. The combined effect of the atmosphere = "atmosphere effect"= thermodyn + radiation.
3. The combined effect of all "greenhouse gases" water vapor, CO2,..= radiation alone.
4. The effect of doubled CO2 without feed-back according to Stefan-Boltzmann with assumed radiative forcing of 4 W/m2 = 1 C = definition of no-feedback climate sensitivity.
5. The real effect of doubled CO2 with feedback = anything between 0 C and 6 C.

Here, 5 is the relevant definition, which however in a discussion can freely be mixed up with any of 1-4. The information about 5 is meager: It can be anything from 0 C to an alarming overheating of up to 6 C, or even cooling.

Which "greenhouse effect" is it then Dick is speaking about together with Fred and Roy, which is not that of Gore and Kiehl-Trenberth, but the one "working in all radiative convective calculations and in GCMs" which give support to Gore's apocalypses??

In politics and religion it is important to not define basic terms clearly, but in science this is completely central in order to make the discussion meaningful. The following questions thus should be answered:

• What is a scientific description of the "greenhouse effect"?
• What are the (possible) effects of the "greenhouse effect"?
• Can they be observed?
• Have they been observed?
• Numbers?

Here is a response to Pierre from Roy, which is I guess directed to me as well:

• Pierre: Since Dick might be too polite to respond, I will.
• When a scientist wants to learn what is known on a certain subject, he/she reads the pertinent literature. This is not easy, but it is also not our jobs to educate you on a difficult subject.
• You could ask me to prove from first principles that force equals mass times acceleration (F=MA), but I am either going to ignore your request, or ask you to read the literature first.
• Your requests waste everyone's time, and you seem to believe a lack of response means your views and criticisms have merit, when in fact they have too little merit to deserve a response.
• If you want to play in this game and be taken seriously, do what scientists do...go do your homework first.
• -Roy

This is a very a clever (not polite) answer, but it has nothing to do with science. I have the impression that alarmists play dirty games, but is it really necessary that also skeptics do the same. If you have science on your side you'd better play a fair game. Right, Roy?

Roy Spencer Slays Back

I have recently challenged Roy Spencer to describe the "greenhouse effect" that he so ardently defends together with Fred Singer, Lord Monckton and Richard Lindzen, an effect supposedly resulting from "backradiation" as heat transfer from cold to warm, which I questioned in Slaying the Sky Dragon.

After thinking quite a bit Roy now hits back with Slaying the Slayers with the Alabama Two-Step with yet another defense of the

• “greenhouse effect” which makes the Earth’s surface warmer than it would otherwise be.

OK, so the "greenhouse effect" is something (not defined) with the effect of making the Earth's surface warmer than it would be without the effect (still not yet defined). No wonder that with this circular definition it is impossible to tell how big this effect may be.

OK, Roys presents the following evidence of the "greenhouse effect" (not defined) in as the Alabama Two-Step:

1. Warming can be caused by a decrease in the rate of energy loss by the climate system (trivial statement).
2. Observation of Outgoing Longwave Radiation spectrum (non-trivial).

I show in From Spectrum to Heat Transfer that quick deductions about heat transfer from a spectrum (like Downwelling Longwave Radiation from cold atmosphere to Earth surface) can be completely misleading. Roy's Two-Step thus scientifically represents a Backward Step.

I do not understand what motivates Roy as a skeptic to spend his energy on slaying other skeptics, rather than taking on the real opponents carrying the flag of CO2 alarmism.

And so: Roy, the arguments you are using to slay the slayers, are scientifically trivial. Wouldn't it be much better to use your energy to come up with non-trivial arguments to beat the alarmists?

Radiative Forcing from Doubled CO2?

Water vapor and CO2 are referred to as "greenhouse gases" GHG because of their effect on the Outgoing Longwave Radiation OLR documented in the above energy spectrum for clear sky over Gulf of Mexico. The effect of CO2 is represented by the dip in the spectrum centered around a wave length of 15 microns. The "radiative forcing" from doubled CO2 of 4 W/m2 underlying the no-feedback sensitivity of IPCC of 1 C, is related to estimated changes of the dip area, with a larger dip area change connecting to larger sensitivity.

On the whole water vapor has a much bigger effect than CO2, and so may easily swamp the effect of CO2. Here is an argument showing that the estimated "radiative forcing" of 4 W/m2 from doubled CO2 may easily be too large.

Consider a a model of global climate with an equatorial region with wet air and a polar region with dry air of roughly the same area, assuming for the discussion that all OLR comes from the polar region.

Radiating 320 W/m2 from the polar region (= 2 x 160 W/m2 insolation) may require an effective temperature of about 0 C, which may be the mean surface temperature in the polar region. This means that the CO2 dip in spectrum will be counted from the lower level (0 C) than in the above figure (about 20 C), and thus have a smaller area.

In this model the effect of CO2 is totally swamped by water vapor in equatorial regions, and in polar regions the dip effect is reduced because the effective radiation temperature is lower.

This is yet another argument indicating that a no-feedback sensitivity of 1 C from "radiative forcing" of 4 W/m2, which is the basic postulate adopted by both alarmists and skeptics like Lindzen, Spencer and Monckton, may have little connection to reality.

It could very well be that the "radiative forcing" from doubled CO2 is rather 1 W/m2 than 4 W/m2, so small that it can never be identified.

Maxwell Believed in Backradiation

The concept of "backradiation", the fundamental postulate of CO2 alarmism, goes back to Prevost's Theory of Exchange (1791) retold in Maxwell's Theory of Heat (1871) as follows:

(p 240-241)

1. ...this character of the transfer of heat, that it passes from hotter to colder bodies, is true the same whether it is by radiation or conduction that the transfer takes place.
2. ...a cold body has no power of acting at a hot body at distance so as to cause it to emit radiations,
3. nor has a hot body any power to stop the radiation of a cold body.
4. ...it follows that if two bodies have the same temperature, the radiation emitted by the first and absorbed by the second, is equal in amount to the radiation emitted by the second and absorbed by the first during the same time.
5. The higher the temperature of a body, the greater the radiation is found to be, so that when the temperatures of bodies are unequal, the hotter body will emit more radiation than they receive from colder bodies, and therefore on the whole, heat will be lost by hotter bodies and gained by colder until thermal equilibrium is attained.

Prevost's theory of exchange from 1791, postulating "backradiation" from cold to hot, was thus picked up first by Maxwell, then by Planck and was then found to be the perfect argument for CO2 alarmism.

Let us scrutinize the logic of Maxwell motivation of two-way transfer expressed in points 2. and 3. above:

• Since a cold body cannot cause a hot body to emit more, a hot body cannot stop a cold body to emit.

Is this a valid scientific argument? Let's make a parallel:

• Since a fool cannot make a wise wiser, a wise cannot stop a fool telling nonsense.

This is the logic of the populism of the web, and so it may carry some truth.

But the following question present themselves:

• Does a similar populism govern physics? Is Maxwell's logic correct?
• Is Maxwell's argument itself populistic rather than scientific?
• Is Maxwell's reference to the authority of Prevost a valid scientific argument?

I have my answers, but I leave the questions open. It would certainly be very illuminating to listen to what a living physicist would say today. Is Prevost's Theory of Exchange still valid, and if so is there any evidence beyond that presented by Maxwell?

Lord Monckton Believes in the Greenhouse Effect

Lord Monckton is reported on WUWT to have baffled his audience at Union College in Schenectady, New York, by opening his “Climate of Freedom” lecture, with a confession to the "greenhouse effect":

• Lord Monckton then startled his audience by saying it was settled science that there is a greenhouse effect, that CO2 adds to it, that CO2 is increasing in the atmosphere, that we are largely to blame, and that some warming can be expected to result.
• But these facts had been established by easily-replicable and frequently-replicated measurements first performed by John Tyndall in 1859 at the Royal Institution in London, “just down the road from m’ club, don’t y’ know” (laughter). Therefore, these conclusions did not need to be sanctified by consensus.

Lord Monckton apparently used tactics which are now common in politics, namely to take on the views of your adversaries. For example, the conservative party in Sweden of today has adopted the views of the social-democrats and vice versa.

But then Lord M pulled the carpet by claiming that the "greenhouse effect" is so small (less than 1 C) that it cannot be detected. This puts Lord M into category 2. of a previous post:

• Skeptics: There is a greenhouse effect, but it is so small that it cannot be detected.

This is like claiming that boys are smarter than girls (or the other way around), but that this "boy effect" (or "girl effect") is so small that it cannot be detected.

So according to Lord M it is "settled science", which is so settled that it does not even have to be

"sanctified by consensus", that "there is greenhouse effect", which however is so small that it cannot be detected. Is this science, or politics or scholastics or what?

Compare with the earlier post Tyndall and His Greenhouse Effect showing that Tyndall assures the existence of an effect

• ...the extent alone of the operation remaining doubtful.

Planck and the Fall of Science

There is a new sequence of posts on The World as Computation about Planck and his role as the father of modern physics, exposed in a larger context in Dr Faustus of Modern Physics.

Can The "Greenhouse Effect" Be Detected?

The recent exhange with Roy Spencer and Fred Singer concerning the "greenhouse effect" and "backradiation" identifies three groups in the climate debate with the following standpoints:

1. Alarmists: There is a greenhouse effect and it threatens to overheat the globe.
2. Skeptics: There is a greenhouse effect, but it is so small that it cannot be detected.
3. Deniers: As long as no greenhouse effect has been identified, one can act as if there is no greenhouse effect.

Roy and Fred belong to 2. and myself to 3. The discussion gets complicated by the fact that "the greenhouse effect" is not clearly described in the literature, but it is somehow connected to the radiative properties of the atmosphere:

Both alarmists and skeptics assume as a starting point that doubled CO2 will cause global warming by 1 C, which is referred to as no-feedback climate sensitivity. Alarmists then inflate it to 3 C with positive feedback and skeptics to about 0.5 C with negative feedback.

Both alarmists and skeptics thus firmly believe that science says that increasing the absorptivity of the atmosphere a little by doubling CO2, will cause warming.

Deniers are not so sure about that referring to the following argument:

• Earth surface temperature is determined by the lapse rate.
• Lapse rate is determined by thermodynamics with radiative forcing.
• Fully transparent atmosphere may be isothermal with zero lapse rate.
• Fully opaque atmosphere may be isothermal with zero lapse rate.
• Reality is somewhere in between with a certain lapse rate.
• It is not clear if more CO2 will increase or decrease the lapse rate.
• It is thus not clear if more CO2 will cause warming or cooling.
• There is no convincing evidence that any effect of doubled CO2 can be detected.

The dividing line goes between alarmists on one hand and skeptics/deniers on the other hand.

The quarrel between skeptics and deniers, about the existence of an effect which cannot be detected, seems to be of minor scientific importance compared to the main question of significant global warming or not.