|Date: Mon, 17 Dec 2001 07:23:09 EST
An excellent review.
I especially liked the first conclusion; viz.
"The mechanism of global warming must be defined in a better manner so that all relevant processes are
However, I have a question.
How are "all relevant processes" to be "represented" when not all relevant processes are known and several known ones (e.g.
effects of clouds) are not understood?
All the best Richard S Courtney
Date: Tue, 18 Dec 2001 08:04:44 GMT
From: "h erren" < email@example.com
I think I discovered a typo:
Insertion of two brackets might clarify the sensitivity equation
dT/dE = 1/(4 [sigma] T^3)
dT/dE = 1/4 [sigma] T^3
Date: Tue, 18 Dec 2001 08:33:39 -0600
From: "BLACK, JACK D. (JSC-NE) (GHG)" < firstname.lastname@example.org
I don't lay claim to any particular expertise in the field of photometric
energy absorption but the Hug-Barrett postulation seems to me to be rationally consistent with the general concepts of atomic energy absorption
and dissipation. It also seems to offer a rationally consistent approach to
explaining the apparent discrepancy between the near-surface temperature
anomalies and the Microwave Sounding Unit/Radiosonde Balloon measurements in
the lower troposphere.
The US National Academy of Science review of these discrepancies in temperature logs essentially found all three to be accurate but offered no
guidance whatsoever for resolution of the discrepancies. It seems reasonable
to at least consider the prospect of energy loss, in the lowest strata of
infrared absorbing atmospheric gases, via collisional energy transfer which
would preclude direct reradiation of absorbed photon energy as is apparently
assumed in the current GCM models. The result of these energy transfers would, it seems to me, be to produce a near surface layer of higher kinetic
energy or temperature while the higher layers responded much more slowly and
function essentially to smooth local variations.
J. Black email@example.com
Date: Wed, 19 Dec 2001 20:33:43 -0700
From: "DAVE DARDINGER" < firstname.lastname@example.org
I'm having a bit of trouble with the 19%, 61%, 20% division of atmospheric
heating from the surface proposed. I see where it comes from, but it looks
to me like not all the requisite figures are being considered. Thus there
are 67 W/m2 absorbed directly from the atmosphere, which presumably is converted into thermal motion and thence into IR radiation, some of which
contributes to the 324 W/m2 back radiation. A more difficult situation is
the radiation emitted by clouds amounting to 30 W/m2. Part of this would
come from the latent heat of condensation from rising water vapor, and part
might come from equilibration with atmospheric gases in general. I'd assume
that most all latent heat released by low level clouds would be reabsorbed
by the higher levels of the atmosphere, while much latent heat released at
high level clouds would be released to space.
The point is that given these other inputs / outputs I'm not sure such precise divisions of contribution to atmospheric warming by various surface
processes can be made.
Fri, 21 Dec 2001 10:36:31 EST
From: Richard Courtney < RichardSCourtney@aol.com
In 'Open Review' of the Hug-Barrett paper, Dave Dardinger says, "The point is that given these other inputs / outputs I'm not sure such precise divisions of contribution to atmospheric warming by
various surface processes can be made."
I agree, and I suspect Hug and Barrett agree too. The significant point is that Hug
and Barrett make this distinction whereas IPCC assumes all thermal exchange in the atmosphere is radiative. This was first explained in IPCC 1990 page 49 where it says;
"The surface, planetary boundary layer and the free troposphere are tightly coupled via air motions on a wide range of scales, so that
in a global mean sense they must be considered as a single thermodynamic system. As a result it is the radiative flux at the
tropopause, and not the surface, that expresses the radiative forcing of the climate system."
Only radiative thermal transfer occurs at the tropopause. And, as the above quotation states, the IPCC makes no distinction
between various thermal effects lower in the atmosphere but assumes they summate to the radiative effect at the
tropopause. Hence, the IPCC asserts that all atmospheric thermal transfer can be emulated as being radiative. Indeed, the IPCC considers
effects of water vapour to be a "feedback" despite water vapour being the major greenhouse gas.
The IPCC assertion is clearly nonsense because if it were true then rain would never happen. But the IPCC has not retracted the
mistake it first made in 1990.
Hug and Barrett may not have partitioned the thermal transfer effects accurately. But they have partitioned them, and this
partitioning is why their analysis provides very different conclusions from those of the IPCC. Large changes to the values Hug and
Barrett assign to the partitions make relatively small change to their results.
All the best Richard
Date: Sat, 22 Dec 2001 13:26:55 +0100
From: Onar Åm < email@example.com
I have no particular expertise in radiative physics, but the Hug-Barrett hypothesis
may be relevant to a little mentioned problem with current climate models, namely the
fact that they appear to COLD. That is, too cold in absolute temperatures. There is
no clear understanding of this phenomenon and one assumes that it does not
significantly affect predictions of warming, i.e. relative temperature changes.
However, the Hug-Barrett hypothesis could potentially explain why models are too
cold. The GCMs assume that the thermal transfer in the troposphere is radiative only.
But if some of this radiation translates into molecular heat, then that would not
only change the radiative behavior of the atmosphere but also the absolute
temperature. Presumably it would be WARMER, consistent with observation.
If my hunch is correct, then it should be possible to partially test the Hug-Barrett
model by implementing it into a GCM and check if the absolute tropospheric
temperature increases to match observation.
Date: Sun, 23 Dec 2001 08:54:00 -0700
From: "DAVE DARDINGER" < firstname.lastname@example.org >
errata from my last note. In " 67 W/m2 absorbed directly from the
atmosphere" should read " 67 W/m2 absorbed directly from the sun by the
Thanks for the clarification by Courtney.
Since my other point might imply that the % of heat transfer within the atmosphere by way of radiation is higher than 20% I'll mention a mechanism
this time in the opposite direction. Since the 61% transfer from evaporation/transpiration only is concerned with the net transfer of heat
from the surface, it presumably doesn't include additional vertical transport of heat within the air column. But in addition to the immediate
transport of latent heat via water vapor there's also the indirect transport
by way of re-evaporation of precipitation before it reaches the ground.
This is known as virga when none of the rain or ice reaches the ground, but
even when it's actually raining, there will be some evaporation on the way
down as long as the underlying air is warmer (which is generally the
case). This results in a net transfer of heat upward as the evaporation cools the
lower layers of air at the expense of the upper layers. I have no idea exactly how large this effect is, nor whether or not it's offset by transfer
of heat from water vapor to other components of the atmosphere. (This last seems unlikely, however, since water vapor would presumably be equilibrated
with the atmosphere as it evaporated.)
Date: Sun, 23 Dec 2001 22:09:45 +0100
From: < email@example.com
> (P. Dietze)
Reply-To: < firstname.lastname@example.org
Jack Barrett and Heinz Hug are to be commended for this paper. But I would like to make a few objections and additions:
> The IPCC explains the phenomenon in terms of radiation and
> imply that molecules do not obtain kinetic energy (heat) by
> absorption of radiation by greenhouse gases.
The Schwarzschild radiative transport equation (which IPCC uses for
model calculation) does not cope at all with what happens to the energy.
Indeed, after absorbing an IR photon, a molecule's excitation is vibrational or rotational. But after collision with other molecules this
energy is converted into kinetic and thus thermal energy. The absorbed energy is calculated using HITRAN spectra. The emitted energy is
calculated from a given temp profile, using Planck's formula for black body radiation and Kirchhoff's law (emissivity = absorptivity) for a number of atmospheric layers.
As the radiative transport equation has no term related to spontaneous re-emission
(contrary to the authors conviction), the emitted energy
must stem from kinetic (thermal!) energy by which the layer temperature
is defined. Btw, the radiative transport equation has no mechanism to force the emitted energy to be equal to the absorbed energy
(i.e. to fulfill the local thermal equilibrium
LTE). IPCC thus may violate the LTE condition if the temp profile is not preset adequately.
> The IPCC state that the air is warmed by contact with
> the warmed soil/ocean surfaces.
I never heard this. I suppose this may be either an erroneous statement from some textbook or a conclusion of the authors, based on their
impression that all IPCC's absorbed energy is spontaneously re-radiated and thus the
atmosphere does not warm up. Actually the re-radiation (and thus back-radiation to ground) from CO2 and the other GHGs is calculated
based on assumed atmospheric warming and the CO2 concentration increment. But in fact more CO2 leads to an increasing lapse rate
(see Ch.3 of my official IPCC TAR Review at
http://www.john-daly.com/forcing/moderr.htm). This results in warming
near ground but radiative cooling starting within the lower troposphere and progressively increasing up to the tropopause. This increased lapse
rate (which could so far not be simulated with atmosphere models)
should be the reason why satellite MSUs measure no significant warming trend in
the range of 1-5 km height.
> The IPCC assumes that photons are recycled by CO2 causing 90%
> of the absorbed radiation to return radiatively to the surface
This is actually not IPCC's figure but stems from Graedel/Crutzen p.47 (Chemie der Atmosphäre, 1994) and deals with near ground radiative
fluxes for the basic natural Greenhouse effect including other GHGs and clouds. My HITRAN calculation for the anthropogenic impact yields a
total absorption of some 7.4 W/m² for CO2 doubling. IPCC says, the forcing
(at tropopause level) is 3.7 W/m². This is 50% and not 90%.
> whereas under the non-equilibrium conditions occurring
> daily in any part of the globe at any time, the [Kirchhoff]
> law is inapplicable
I am quite sure that Kirchhoff's law (i.e. emissivity is equal to
absorptivity) which is used in the radiative transport equation, holds
under any circumstances and does not require thermal equilibrium. As long as cool air is warming up during a sunny day, the emitted energy is
less than the absorbed energy, but still emissivity = absorptivity (denoting a material property). The law does not say that absorbed
energy = emitted energy. The authors may have misinterpreted this.
Heinz Hug's lab results in Fig.1 are very interesting, revealing that the absorption of CO2 is considerably enhanced by IR-neutral gases like
nitrogen - which so far has not been coped for by HITRAN and which can by no means be explained by pressure broadening or equipment fallacies.
But the problem whether this may lead to more or less residual absorption
(for CO2 doubling) at the fringes, could not be solved. Heinz
uses this finding rather to prove that thermalization by molecular collision really takes place. But I think, this debate versus assumed
spontaneous re-radiation of IPCC is not very fruitful as it makes (macro-energetically) not much difference whether the absorbed energy is
directly re-radiated by CO2 or thermalized and then re-radiated. Of course, thermalization would yield a different heat and spectral
distribution within the troposphere, but any difference in ground warming is difficult to quantify.
Jack Barret's chapter 4 about atmospheric sensitivity really reveals IPCC's exaggeration factor 3.7 - this has been excellently presented at
the DECHEMA colloquium. In chapter 5 Table 2 Jack shows that the delta absorption for a 100 m layer and 2*CO2 without vapor is 1.7 %, but with
vapor it is only 0.7 %. But the wavenumber interval for which this was integrated, is missing.
> Hug emphasized that at a height above the ground of
> 1000 m 97% of the carbon dioxide bands are saturated
This only holds for the linestrengths (molecular extinctions)
which are not representative for energy absorption. There are always fringes that
are not saturated and this is why we have the same forcing in W/m² each
time CO2 is doubling.
> that the spectral overlap, ignored by the IPCC, is the
> reason for the sensitivity being exaggerated by the IPCC
It is not only the vapor overlap, but another fact is that IPCC relates the 3.7 W/m² to 255 K
(yields 0.98 K) whereas if it is related to
near ground, we get 0.68 K only. Apart from double the forcing (by not coping with vapor overlap) IPCC uses about a 2.5 times vapor feedback.
But acc. to Bengtsson et al. (JGR Feb 1999) most of the troposphere is cooling with more CO2
(as observed). The lower regions where the
clouds are, may be hardly affected. As the whole troposphere may even contain less vapor, the strong vapor feedback should rather be a fairy
tale. Only near ground we will have a vapor increment. Alltogether IPCC's CO2 sensitivity is probably by a
factor four too high and thus the vapor increment near ground is considerably reduced. The great
differences in cloud forcing shown in Fig.3 are really eyestriking.
Thanks to Jack.
Date: Thu, 17 Jan 2002 12:05:59 EST
From: Jack Barrett Jack1Barrett@cs.com
Richard Courtney's contributions are welcome. Hans Erren's clarification of
the derivative of the Stefan-Boltzmann equation is good; you could get a very
funny result if the T^3 term was understood to be above the line. Dave
Dardinger's comments are valid. The 67 W m^-2 absorbed by the atmosphere are
discounted in our calculation of the contribution to warming by radiation.
The 67 W m^-2 are absorbed in the stratosphere (10) and the upper
troposphere. Some (but how much) will contribute to downward radiation. We
could do a 'Solomon' on it and say half comes down and the other half goes
up, but the main point is that not 100% of the warming is due to radiation.
The 30 W m^-2 cooling from the cloud-tops is part of the diagram, but I don't
know its origin. If Stefan-Boltzmann is applied, the cloud tops are very cool
Date: Sun, 27 Jan 2002 15:30:31 -0800
From: Craig Wheelock < craige@QNET.COM
Readers and Staff,
I hereby challenge all readers of this note to provide me with quantitative and reproducable evidence of the
re-radiative properties of CO2. I have been searching for some time, and have come to
the conclusion it is non-existant.
Craig Wheelock < email@example.com
Date: 11 Feb 2002
From: Heinz Hug and Jack Barrett
Reply to Peter’s criticisms
In the same order that they appear
n)/B21(n)] * C(n, T). The term C(n, T) describes
especially the radiative thermodynamic equilibrium and includes the
Boltzmann factor. If the spontaneous emission A21(n) were zero there would
be no emission – also no "thermal emission". If the
stimulated emission in the radiation field were zero (B21(n) = 0) then the emission
would be infinite. Instead of L (radiation to space) the term B
(brightness) of a layer is also in use by some authors. In both cases
Planck emission is assumed.
- From H & B point 2.
(a) We have no quarrel with the Schwarzchild
equation or its applicability. Its two terms are connected with the
heating (absorption of photons) and cooling (emission of photons) of
the atmosphere as radiation passes from the surface to space. The IPCC
object to our interpretation of the heating rate in terms of
thermalization of the absorbed energy, but it seems to us that there
is no difference in understanding of the equation. The emitted energy
is approximately calculated by using the Planck emission moderated by
the absorption coefficients for the molecules participating and at the
various temperatures along the optical path. There are uncertainties
in such measurements.
(b) The Planck emission equation contains both
Einstein A and B factors and if either was to have a zero value the
Schwarzchild equation would not work. In a very simplified version the
Planck emission can be formulated as: L = [A21(
(c) Local thermodynamic equilibrium means that the
collision rate is sufficient to maintain the Maxwell-Boltzmann
distribution of velocities, and the values of the Boltzmann factors
for the molecules of the atmosphere. It does not mean that there is
anything like a true equilibrium in existence. LTE breaks down only at
high altitudes (>85 km) when the fraction of vibrationally excited
CO2 molecules is less than that given by the Boltzmann
factor and where radiative emission predominates over collisional
(d) We can only repeat that the IPCC people at the
Frankfurt conference maintained that the atmosphere in contact with
the surface was mainly heated by the physical contact [whether they
meant thermal conduction or that plus convection and evaporation we
are not sure] rather than by any radiative processes. We strongly
disagree with their point of view.
A similar testimony can be found in the book by
Gary E. Thomas and Knut Stamnes "Radiative Transfer in the
Atmosphere and Ocean". [This book is highly recommended by us.]
Prof. Raschke and other modellers refer to it, and it describes the
fundamentals of radiative transfer as assumed by the IPCC. The authors
call the thermalization or quenching an "inelastic collisional"
process and say: By inelastic collisions "energy is
transferred from kinetic to internal excitation energy, or vice
versa. An elastic collision is one in which there is no net
transfer of energy from kinetic to excitation energy (p. 99)." At
the same page, figures are given which assume that thermalization
(quenching by inelastic collisions) is of less interest: "Elastic
cross sections are of order 10-19 m2 Inelastic cross
sections are much smaller; of order 10-23 to 10-25 m2 (p. 99). There is a remark (Note 15 at p. 128)
about the significance of these numbers: "If inelastic cross
sections were not much less than the elastic, there would be drastic
consequences. Consider air at sea level, for which ~109
collisions occur [per molecule, our addition] per second. If a
significant fraction of these collisions were inelastic – leading to
an eventual radiative loss of heat – the air would cool down almost
instantaneously!" Thus, the only conclusion remains: The basic
theory of modelling assumes that the radiation that had been emitted
by the soil escapes through the "open window" or is absorbed
by greenhouse gases. In the latter case the absorbed energy is
transported in the air only by radiation. Thermalization is not
assumed in any case. The only way in which kinetic energy of air
molecules can be attained is by the direct contact between air and
soil (or water). Thermalization is excluded by the theory of radiative
transfer. This had been confirmed at the DECHEMA by the modellers.
Reading only the IPCC papers for "policy makers" or other
papers in Science, Nature, etc., should not be the base
on which the main error can be discussed.
(e) You say that the energy budget reference should
be to Graedel and Crutzen. They may have the same diagram, but our
reference is correct. The diagram (and that of Graedel/Crutzen
presumably) is based on the original data given by Kiehl and Trenberth,
Bull. Am. Met. Soc., 78, 197, (1997). The diagram
indicates values for all fluxes occurring in the atmosphere, not just
those near the surface. Your model does not reproduce the experimental
observations, and the fraction of 50% radiation returning to the
surface value is your choice.
There is more than one explanation of the
greenhouse effect. One is based on calculating the increase of
long-wave radiation remaining in either cloudless or cloudy atmosphere
(G. Myrhe, E. J. Higwood, J. P. Shine, F. Stordal (1998) Geophys
Res Lett 25, 2715. Another concept compares the thermal
radiation from the ground with emission to space over the same area.
The values range between 100 and 250 W m-2 depending on the geographical region and season (E. Raschke,
Fresenius J Anal Chem (2001) 371, 791. The last theory
copes with that what H & B are saying. They mean that the GE is
caused more by thermalization and delayed emission (delayed by
previous collisional and bulk transfer processes) to space by the
atmosphere over the whole day (day & night) and the Earth’s
surface. The solar energy absorbed by the Earth’s atmosphere has a
residence time of around 124 days, not a figure that would be
consistent with processes all occurring at the speed of light.
(f) We agree with Richard’s comments on the
From H & B point 3.
The linestrengths reported are from real spectra
and are a measure of absorption; they are integrals of the absorption
coefficients over the spectrum. This is the conventional way of
representing the intensity of a transition rather than just the
absorption coefficient at the frequency of maximum absorption, the
latter measurement being subject to the pressure of the system.
From H & B point 5.
The data arise from experimental observations and the
IPCC exaggerates its relevance.
Date: Fri, 08 Mar 2002 18:24:45 -0500
From: "Andy Harris" < Andy.Harris@noaa.gov
I think there is a problem with the assumption that IPCC believe all heat transport within
the atmosphere is radiative. The problem is two-fold. Firstly, the IPCC do not believe
anything of the sort. The models used are derivatives of those developed for numerical
weather prediction, and most definitely have convection, precipitation, latent heat
exchange and many other processes represented in them. Secondly, the selective quoting of
the IPCC executive summary and subsequent misinterpretation is more than a little
disturbing, especially when found on a web site that frequently makes allegations of a
rather similar nature. Most climate scientists are quite realistic in assessing their
current best estimates of the reliability of predictions. It is these same scientists who
author the chapters in IPCC. For the record, I shall give my interpretation of what
appears to be a most misunderstood phrase:
"The surface, planetary boundary layer and the free troposphere are tightly coupled via
air motions on a wide range of scales, so that in a global mean sense they must be
considered as a single thermodynamic system. As a result it is the radiative flux at the
tropopause, and not the surface, that expresses the radiative forcing of the climate
The first sentence states that transports of heat via radiation, convection, etc. serve to
couple the vertical distribution of tropospheric temperatures. Above the troposphere,
vertical atmospheric motions are greatly reduced by the change in sign of the temperature
gradient, thus effectively decoupling the stratosphere from the troposphere in all heat
fluxes except radiation. Thus, so says the second sentence, the radiative forcing of
climate is best expressed at the tropopause. Radiative forcing is therefore considered to
be the imbalance between incoming and outgoing radiation at the tropopause.
I'm assuming that Hug and Barrett realize all this already, but others appear to be less
aware of the definitions. The thing that concerns me the most is that some people assume
that such a massive scientific investigative effort would have been based on such a
demonstrably false premise.
I may return to the meat of Hug & Barrett at a later date.
Andy Harris Room: 711-K
NOAA/NESDIS ORA Tel: +1-301-763-8102 x169
World Weather Building Fax: +1-301-763-8108
5200 Auth Road E-mail: Andy.Harris@noaa.gov
Camp Springs, MD 20746 Web: www.nesdis.noaa.gov
Subject: IPCC modelling procedure
Date: Sat, 9 Mar 2002 06:18:38 EST
From: < RichardSCourtney@aol.com
To: < firstname.lastname@example.org
Andy Harris writes of me:
"I'm assuming that Hug and Barrett realize all this already, but others appear to be less aware of the definitions. The thing that
concerns me the most is that some people assume that such a massive scientific investigative effort would have been based on
such a demonstrably false premise."
I assume nothing. As an Expert Peer Reviewer for the IPCC I am fully aware of the contents of IPCC Reports and I quote them
accurately. The IPCC assertion I quoted simplifies the methodology of General Circulation Models
(GCMs) used to emulate the Earth's climate system. The GCMs use finite difference analysis
(fda) to determine atmospheric conditions in a 3-d grid over the
Earth's surface. So, when using a GCM, input of a change to the radiative flux at the tropopause induces the modelled effects at
each fda grid point to change their magnitudes. But, and importantly, this modelling procedure requires an assumption that the
effects of changes to the greenhouse effect in the lower troposphere are known to a degree that permits input of their resulting
change to radiative transfer at the tropopause.
The other effects lower in the atmosphere are assumed to be known with sufficient accuracy for them to reach fda stability.
I would prefer people to use facts and arguments and not insults when challenging my statements.
Richard S Courtney
Subject: Re: Bad science is quite normal
Date: Thu, 14 Mar 2002 02:42:57 -0500
From: Jim Clarke < email@example.com
Andy Harris wrote:
"The thing that concerns me the most is that some people assume that such a massive scientific
investigative effort would have been based on such a demonstrably false premise."
Does Mr. Harris find it difficult to believe that a 'massive scientific investigative effort'
could take place on a totally faulty premise that was easily proven false. He shouldn't be.
Throughout history, the scientific community has often clung to and tried to advance ideas that
where already proven false. The whole concept of man-made global warming is based on the premise that an increase in CO2 in
the Earth's troposphere will cause an increase in air temperature of the troposphere. Few
doubt the truth of the premise and that is not the issue. The issue is the amount of warming
generated by the increase in CO2. The only reason that man-made global warming became a
massive issue is that computer models predicted a dangerous amount of warming from the
increasing CO2. In reality, the 'massive scientific investigative effort' is based on the premise that global
climate models can predict future climate with some degree of accuracy. In high school we all
had to include the degree of accuracy that we could claim with our lab experiments.
"The experiment produced 6.2 ml. of liquid, plus or minus .05 ml." If the climate modelers were
required to do the same, their report would read: "A doubling of CO2 will produce a warming of
3-5 degrees, plus or minus 40 degrees."
There are far too many 'unknown variables' in the models that are just given a value. While
that value may be an honest guess, it still carries a degree of inaccuracy that only multiplies
when coupled with other assumptions and run through complex equations. The results of these
models have little meaning. Even James Hanson, one of the founding fathers of the global
warming scare, now openly admits that the models can not predict future climate with a degree
of accuracy sufficient to influence policy decisions. While study of climate and climate change is worthy, most of the funding for such study is
being generated by the global warming scare, which is based entirely on the assumption that
computer model forecasts have a meaningful degree of accuracy, which is a 'demonstrably false
premise' and has been from the very beginning.
The models are meaningless and yet we spend billions because of what the models say. You
should not be surprised. The history of mankind is filled with such behavior.