1 A Critical Examination (December 18, 2012) by Dr D Weston
Allen of: A Discussion on the Absence of a Measureable Greenhouse
Effect By Joseph E Postma (October22, 2012) Introduction: After two
earlier papers attacking the Greenhouse Effect (GHE), Understanding
the Thermodynamic Atmosphere Effect (March, 2011) and The Model
Atmospheric Greenhouse Effect (July 22, 2011), both of which I have
critiqued, Joseph Postma now presents this comprehensive assault on
the theories of global warming by atmospheric greenhouse gases
(GHGs): heat trapping, backradiation and elevation of the radiative
emission level. Over three weeks after I sent this critique to him
via John OSullivan, Postma responded, but only to my introduction
and last paragraph of the conclusion nothing in between. I have
therefore clarified the statements and mathematics that he
struggled to comprehend and added much of his response (in blue) to
this introduction. In the Introduction to his Absence paper, Postma
points out that the GHE is supposed to explain the 33C difference
between Earths mean near-surface-air temperature and the global
effective blackbody temperature calculated from the absorbed energy
from the sun. He then takes the novel approach of postulating what
would happen if there were no GHGs in the atmosphere. He first
shows that Earths albedo (reflectivity) would not be 0.3 (30%) but
just 0.04, in which case the calculated surface temperature would
not be 33K below the observed mean but only 12K less. He overlooks
the fact that atmospheric aerosols and major gases also reflect and
absorb solar rays, however, and also that the surface albedo of
0.04 relates to the solar flux at the top of the atmosphere (TOA).
Removing the GHG/cloud filter would allow a greater percentage of
TOA flux to reach the surface and thus be reflected there, in which
case the surface albedo would be more than 4% of the TOA flux. Such
basic logic seems lost on Postma: This author doesnt even know how
to kindly address this. It is one of the stupidest things I have
ever read, and exposes the fact that Wes probably has no
understanding of the meaning of the term albedo. Whereas Postma
calculates the mean surface temperature of a sunlit hemisphere with
an albedo of 0.3 and no atmospheric absorption to be +49C, my
calculations put it at 34C; and at just 5C with atmospheric
absorption (and no GHE). That is about 10C below the observed mean
for the entire half-dark planet. But Postma objects: Wes does not
actually provide any explanation for how he arrived at his values,
and so we might only assume that he is guessing at them out of thin
air. The relevant section in my paper clearly describes how I
calculated the value I did: the instantaneous average heating
potential of sunlight over the sun-facing hemisphere, assuming an
integrated albedo of 0.3, has a hemispherically integrated average
value of 322K or +49C. If that clearly describes Postmas method,
Ill eat my hat! I had given at least the equivalent explanation.
For Postmas sake, and to leave the reader in no doubt, however, I
have now fully explained the science and maths behind my figure of
34C on page 7 of this critique. Postma says the 33K attributed to
the GHE can be explained by the lapse rate (reducing temperature
with increasing altitude), which he derives from first principles
without reference to a GHE. He now asks: does Wes care to argue
that the successful derivation of the dry lapse rate only
coincidentally matches that of what is observed? Whereas the
derived dry adiabatic lapse rate is ~9.8K/km, the observed mean is
~6.5K/km. Is that a coincidental match? Ignoring the term
adiabatic, Postma confuses the moist adiabatic lapse rate with the
observed environmental lapse rate, both in his paper and in his
response: This is a great example of the type of sophistry that
frauds enjoy to use 2 in their multifaceted obfuscations in all
things science-related. The observed environmental lapse rate and
the moist lapse rate are entirely the same thing. Are they really?
The moist adiabatic lapse rate is only ~5.5K/km. It relates to
fully saturated air whereas the environment is only partly
saturated with water vapour. Whenever Postma is caught out, in this
case using incorrect terminology, he forgets truisms about judging
others as oneself or pointing the finger, and accuses his critic of
sophistry, a subtle, tricky, superficially plausible, but generally
fallacious method of reasoning. Guestimating the water vapour at
Earths surface to be 2.5%, based on Wikipedias range of 1-4%,
Postma calculates an environmental lapse rate of 6.24K/km; and then
works backwards from 6.5K/km to determine a mean water vapour
content of 2.29%, over 8% below his guestimate. He nevertheless
asserts: The calculations I presented between pages 7 and 9 of my
Absence paper were a demonstration of the ability to successfully
predict the average environmental lapse rate given the known
surface-level water vapour concentration, and an estimate for the
height of the troposphere and vapour concentration therein. Local
conditions will of course vary, and the calculation using
average-known values was entirely successful at predicting the
observed rates. When calculating the impact of latent heat on the
lapse rate, Postma assumes that it is linear, that the atmosphere
is in hydrostatic equilibrium and that the tropopause is at a fixed
altitude. He overlooks the non-adiabatic absorption and emission of
infrared radiation by atmospheric GHGs and their role in assisting
the heat pump that drives the lapse rate, in rendering it more
uniform and in determining its extent. Instead of properly
addressing this, Postma prefers innuendo and ad hominem: Here, Wes
seems completely oblivious to the concept of physical averages.
This is not surprising since he is unfamiliar with the appropriate
usages of mathematical averaging, as evidenced by his support for
flat-earth models of the terrestrial environment as so much from
the dark ages, and his apparent lack of undergraduate training in
math and physics. . . Undoubtedly, this is why Wes prefers to deny,
yes, deny, in one of the absolute worst of possible human ways,
standard mathematics, physics, and logic. It is the denial of
rationality itself, representative of the gnostic demiurge. Are
these the words of a scientist or of an offended religionist? For
the record, I excelled in my undergraduate maths and physics; but
the veracity of any argument or insight is not based on the
qualifications of the protagonist. Einstein is a prime example. In
his second section, Postma uses heat-flow mechanics and time
constant (tau) values incorporated into a formula in which a
surface cooling variable (for conduction, convection, evaporation
etc) was removed (contrary to his text) and replaced with a second
GHE warming variable. He used this to produce impressive surface
temperature graphs using selected GHE variables. His modified
formula [16] is thus fundamentally flawed and hence his temperature
responses are positively biased. Postma responds: Wes seems to
understand nothing of what was actually presented with that
equation and its modelling. First, Wes seems to think that the
heating strength of the GHE must at all times be equal and opposite
to the cooling strength of the air! This is absurd beyond belief,
as it was discussed in my paper. Just look at the cognitive
dissonance and the abuse of logic in this: the atmospheric GHE
causes heating, but observing it is impossible because the
atmosphere causes cooling. !!! This is a perfect example of Satanic
thinking, a perfect example of the gnostic characterization of the
demiurge. Postma puts words in my mouth and then condemns them,
even labelling them Satanic thinking! Postma himself is guilty of
cognitive dissonance in his Absence paper, emphasising conduction
of heat to the atmosphere when it suits and forgetting all about it
when it doesnt. Does he now deny any conductive cooling of Earths
surface by the atmosphere? Thoughtful readers could be forgiven 3
for wondering why I bother with Postma: even if he is beyond
reason, I sincerely hope that some of his devoted followers arent.
Postmas third section compares the GHE graphs produced using his
flawed formula to those based on observations made by Carl Brehmer
at Chino Valley in Arizona over two days in June 2012. Of course
Brehmers findings dont support Postmas contrived GHE graphs; but
Postma ignores conduction, convection and humidity. When these are
factored in and Brehmers data is carefully analysed, it strongly
supports the GHE. Postma responds: It is very clearly derived how
the GHE should be observable [from his flawed formula]. It wasnt
observed [at first glance]. And so therefore GHE advocates do a
volteface [sic] on the entire matter and now claim that the
atmosphere is *such an efficient cooler*, that it cancels out any
heating effects of the GHE on the surface! Yes, such is the nature
of the laughable sophistry of Dionysus. Again the Postma calls the
kettle black. Whereas GHE supporters have always recognised that
the atmosphere cools Earths sunlit surface by conduction, and
factored it into their energy budgets, Postma paints them as doing
a volte-face on the matter. And he does so to obscure the fact that
he completely overlooked conductive cooling of the surface in
Brehmers experiment. There is very little relevant science and a
great deal of sophistry and philosophy in the remainder of this
rather lengthy paper. Precious Postma takes great umbrage at this
comment: on the very first page of his critique he himself makes an
ad-hominem, patronizing, and judgemental comment. If you have
wondered why I have not been kind to Wes in this review of his
review, it is for this reason. Wes is simply not a competent
scientist or mathematician nor can he understand or critique
standard scientific research in a competent let alone professional
way. It is a waste of my time to attempt communicating scientific
concepts with ideologues such as this and I wish for my judgement
on this matter to be blatantly understood. I admit that my
statement was judgmental of Postmas paper but not of his person,
learning or integrity. It was not in the least ad hominem. He
assumes that I was referring to his arguments, rather than those he
quotes, as sophistry. Unable to differentiate criticism of his
paper from that of his person, Postma lashes out with actual ad
hominem that I find quite amusing. I am delighted that he could
find no fault with my critique other than a couple of poorly worded
sentences, but disappointed that he could not bring himself to
admit a single error or concede a single point. His emotional
response to my critique reveals a greater concern for ego than for
science. Instead of the absence of a measurable GHE, Postma
unwittingly presents strong evidence to support it. (Quotes from
Postmas Absence paper are hereafter highlighted in red.) 4 1.
Introduction to the GHE 1.1. The problem, and truth, of the albedo
Generally, the inference of an atmospheric GHE is made by comparing
the Earths near-surface-air average temperature to its global
effective blackbody radiative temperature calculated from the
absorbed energy from the Sun there is a difference of 33K. There
exists a simple contextual flaw in this inference because the
average terrestrial albedo is much higher than the true surface
albedo due to the presence of clouds in the atmosphere, resulting
in a terrestrial albedo of approximately 0.3, while the true
surface albedo is actually much less at only 0.04 [3]. That is,
without greenhouse gases, the albedo would not still be 0.3, but
0.04. . . . It should be noted that the much higher albedo, with
GHGs present, is caused by the presence of clouds from
droplet-condensation of the GHG water vapour. [p.3-4] Postma bases
this figure of 0.04 on Donohoe and Battisti (2011),1 whose
satellite data confirmed earlier modelling that the vast majority
of the observed global average planetary albedo (88%) is due to
atmospheric reflection. While the remaining 12% (of the total 0.3)
occurring at the surface is indeed only about 0.04, Postmas
conclusion is wrong for the following reasons: 1. Across Earths
varied surface, the albedo is greater than 0.04 everywhere except
over still water with an overhead sun. The albedo over land areas
is mostly in the range of 0.1 to 0.4 (increasing from forest to
grassland to desert sand, consistent with the value of 0.26
obtained by Carl Brehmer and quoted by Postma on page 26); over
water it ranges from 0.035 to 0.38 (as the sun sinks from 90 to 10
above the horizon); over ice it is 0.5 - 0.7 and over snow 0.8 -
0.9. The mean surface albedo is therefore much greater than 0.04.
On page 5, Postma himself postulates a surface albedo of 15% (0.15)
with no clouds in the way. 2. The figure 0.04 means 4% of solar
radiation at the top of the atmosphere (TOA), not 4% of that
reaching the surface. In addition to the 26% reflected by the
atmosphere, another 20% or more is absorbed by it, much of it by
greenhouse gases (GHGs) and clouds. Over a third more solar
radiation would reach Earths surface if there were no GHGs,
particularly water vapour; and so more than 5% of the TOA flux
would be reflected at Earths surface. 3. Solar radiation is also
scattered / deflected by the major gases, nitrogen and oxygen, by
Rayleigh Scattering (discussed by Postma on page 26). This is
inversely proportional to the fourth power of the wavelength, which
is why the shorter blue wavelengths are scattered more than red,
and Earth looks blue from space. Atmospheric dust, sulphur and
other aerosols also reflect sunlight. The combined effect of this
scattering is thought to contribute as much as 0.06 (6%) to Earths
albedo and clouds 20% (Fig. 1). Figure 1: Interaction of Solar
Radiation on Earths Atmosphere and Surface Source:
http://www.ucar.edu/learn/1_3_1.htm (I have been unable to find
corroborating evidence for this figure of 6%) 5 Water droplets in
clouds, of course, have nothing to do with water vapours GHE. Being
unrelated to GHGs, this ~0.06 would need to be added to the surface
albedo in Postmas scenario. Without any atmospheric greenhouse
gases, therefore, Earths albedo would be much greater than 0.04, at
least 0.1 and probably about 1.2. Indeed, Donohoe and Battisti
point out that the atmosphere attenuates the surface albedo by a
factor of 3. Therefore a valid comparison is actually found in the
theoretical temperature of the Earth-ensemble without greenhouse
gases (GHGs) and with a correctly corresponding albedo, to that
with greenhouse gases with their corresponding albedo. In this
physically meaningful comparison, the difference in temperature
between the theoretical ground surface, and the observed surface
with an atmosphere and GHGs on top, is only 12K, reducing the
inferred strength of the GHE by almost two-thirds. That is, the
average global surface temperature without GHGs, calculated using
the usual method of the Stefan-Boltzmann Law with conservation of
energy given the known solar input and the surface-specific albedo,
results in a value of 276K. The observed average surface
temperature with GHGs present is actually 288K (15C), and so the
greenhouse effect should actually be thought to only provide 12K
worth of additional temperature, not the 33K which is always
incorrectly cited. [ibid] Postma doesnt say exactly what known
solar input he uses. Recent measurements put it at 13633 W/m2, but
his appendices indicate a reliance on 1370 W/m2. I use 1368 W/m2 in
my calculations. Postmas albedo of 0.04 leaves ~1313 W/m2 to warm
Earths surface; spread evenly over the globe by dividing by four
gives ~328 W/m2 from which the Stefan-Boltzmann equation gives an
equilibrium temperature of ~276K (3C). Had Postma used an albedo of
0.1, he would have derived a surface temperature of 271.4K; and an
albedo of 0.12 would result in a temperature of ~270K, 18K below
the observed mean. Although Postma mentions the absorption of solar
radiation in the atmosphere, he ignores it in his calculations.
Only about half of the absorbed solar radiation is in the infrared
spectrum (Fig. 2). Figure 2: Solar Radiation Spectrum at Top of the
Atmosphere (yellow) and at Sea Level (red). Source:
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png At an altitude
of 100-200km, almost all wavelengths shorter than 100 nm are
absorbed by molecules of oxygen and nitrogen, resulting in
electronic transitions into atomic ions. The upper mesosphere
absorbs the Lyman-o radiation at 121.6 nm. Photodissociation of
oxygen absorbs the Schumann-Runge continuum (130-175nm) at 80-120km
altitude, and the 175-200 nm band is absorbed by photodissociation
and vibrational transitions of the oxygen molecule at an altitude
of 40-95km. Oxygen atoms and molecules combine in the stratosphere
to form ozone, which absorbs about 99% 6 of the UV shorter than
320nm.2 This, of course, is unrelated to any IR-absorption by
ozone. Joanna Haigh describes these absorption bands in The Sun and
the Earths Climate: The oxygen Herzberg continuum is found in the
range 200 242 nm and is overlapped by the ozone HartleyHuggins
bands between 200 and 350 nm which are responsible for the
photodissociation of ozone below 50 km. The ozone Chappuis bands,
in the visible and near-infrared, are much weaker than the
aforementioned bands but, because they absorb near the peak of the
solar spectrum, the energy deposition into the atmosphere is
significant. Furthermore, this deposition takes place in the lower
atmosphere and so is particularly relevant for climate. The
absorption of solar near-infrared by carbon dioxide and water
vapour is smaller but makes an important contribution to the heat
budget of the lower atmosphere. 3 The altitudes of these absorption
bands and the gases responsible are illustrated in figure 3. Figure
3: Wavelength dependence of the altitude of one optical depth for
absorption of solar radiation with an overhead Sun. After Andrews
(2000). Oxygen also absorbs about 2 (0.9-3.11) W/m2 of solar energy
in the 300-1300nm band.4 Aerosols not only reflect solar radiation
to space but also absorb it, mostly in the visible spectrum,
resulting in global dimming. Based on visibility measurements at
3,250 meteorological stations around the world (and satellite data
from 2000 to 2007), Wang et al (2009)5 found a steady global
increase in aerosols from 1973 to 2007, except over Europe which
experienced global brightening. The percentage of TOA solar flux
absorbed by the atmosphere was thus increased to 22.9% in 2008.6 If
we accept a terrestrial non-GHG albedo of 0.12 and non-IR
atmospheric absorption of 11.5% of the TOA solar flux, only ~281
W/m2 would reach the surface, sufficient for a temperature of
~265K, or 23K below the observed mean. If we accept an albedo of
just 0.1 and a third of atmospheric absorption (7% of TOA flux) as
being unrelated to GHGs and clouds, this would result in ~295 W/m2
being absorbed by the surface and a temperature of 268.5K, still
7.5K below his 276K. Although Postma discusses the emissivity of
Earths surface, he fails to factor it in. A conservative emissivity
of 0.96 would increase the surface temperature from 268.5K to
~271K, still 5K below Postmas 276K and 17K below the observed mean.
A very significant difference remains to be explained. On page 5,
Postma points out that, viewed from space, Earth has an apparent
blackbody temperature of 255K, which is the temperature of the
average radiating emission altitude . . . between 5 and 6 km. . . .
exactly the temperature it is supposed to be. Of course! 7 He
further explains that temperature increases with depth below this
layer because the bulk source of heat energy . . . comes from solar
radiation generating heat at the bottom-most layer of the
atmosphere, at the surface-atmosphere boundary. He then correctly
calculates that with a surface albedo of, say, 15%, and no clouds
in the way, the real-time insolation temperature works out to ~378K
or 105C, via the Stefan-Boltzmann Law. [But he then continues] As a
matter of fact, the instantaneous average heating potential of
sunlight over the sun-facing hemisphere, assuming an integrated
albedo of 0.3, has a hemispherically integrated average value of
322K or +49C. Responding to my initial draft of this critique,
Postma stated: There is nothing that is physically or
mathematically ambiguous about this statement, unless the person
reading it is entirely devoid of knowledge of undergraduate-level
science and mathematics. I had stated: According to my
calculations, the mean solar flux over a hemisphere with no
atmospheric absorption and an albedo of 0.3 would be ~479 W/m2 and
the corresponding temperature would be ~307K or +34C. Since Postma
then makes the accusation: However, even with Wes guessed at value
of +34C . . ., here are my calculations: TOA solar flux 1368 W/m2
Minus albedo of 0.3 ~ 410 W/m2 = Absorbed flux 958 W/m2 This would
be the flux absorbed over a cross-section of Earth through the
centre (i.e. a disc), not a hemisphere, which has a surface area
twice that of its base (disc), so we have to halve this figure: =
479 W/m2 To determine the average hemispheric temperature from this
insolation, we use the Stefan-Boltzmann (S-B) equation: E =oT4
(W/m2) Where E is radiated energy, T is in Kelvin (K) and o is the
Stefan-Boltzmann constant: ~5.67 x10-8. For a blackbody in
radiative balance, outgoing radiation equalling incoming radiative
flux, the temperature produced by incoming radiation can thus be
derived: T = (E/o)4 For a grey body such as Earths surface with an
emissivity (c) less than 1, the S-B equation becomes: E =coT4 and T
= (E/co)4 Assuming an emissivity of 0.95 for Earths surface, T =
(479/(0.95x5.67x10-8))-4 = (8,888,888,889)-4 = 307K = 34C Had I not
allowed for emissivity (i.e. regarded the surface to be a
blackbody), the sunlit hemisphere would have a mean surface
temperature of only 303K or just 30C. Postma is therefore out by at
least 15K. If we then allow for atmospheric absorption of 22.9% of
the TOA solar flux, we would have to subtract another 313 W/m2 from
the 958 W/m2 to give 644 W/m2 and divide that by 2 to give a
surface flux of just 322 W/m2. Plugging that figure into the above
equation gives a temperature just 278K or 5C. Since Earth rotates
too fast for equilibrium to be reached, the sunlit hemisphere would
be even less than 5C, over 10C below the observed mean for the
entire half-dark globe! It is much warmer than that, of course,
thanks to downwelling IR from an atmosphere that is warmed from
above and below. 8 1.2. The lapse and cloud-height forcing On page
7, Postma discusses the lapse rate (I), the flux-weighted mean
radiating altitude (H) and the formula of Hansen et al (1981)7
relating IH to the observed surface temperature (Ts = 288K) and
effective blackbody temperature (Te = 255K): Ts ~ Te + IH Thus IH =
288K 255K = 33K He then states: Unfortunately, Hansen (et al.)
(ibid) do not state the actual mechanism by which IH arises, nor
were any references made for such, but it is apparent they
considered it (IH ) to be representative of the GHE itself. The
lapse rate I (both dry and wet values of it, as we will see) can be
derived from first principles. Postma correctly shows how the dry
adiabatic lapse rate (Id) can be thus derived, ultimately from
gravity (g = 9.808 m/s2) divided by the thermal capacity or
specific heat (Cp) of air (1.005 kJ/kg/K), so that: Id = 9.76 K/km.
(Postma uses 9.8 and 1.006 to derive Id = 9.74 K/km) Postma calls
this simply the lapse rate rather than the theoretical dry
adiabatic lapse rate, the change in temperature as a parcel of dry
air moves up or down while exchanging no energy with its
surroundings. It is not to be confused with the actual
environmental lapse rate which is not adiabatic and varies across
space and time. As per Postma on Hansen et al, it is apparent he
considers it (IH) to be representative of gravity and specific
heat; but how does that explain the fact that the lapse rate drops
to zero at the tropopause? Gravity doesnt suddenly drop to zero,
nor does the specific heat of air soar to infinity. The simple
reason is that warming from above equals that from below at the
tropopause; and this has much to do with IR-absorbing/emitting
gases. A lapse rate is entirely dependent on a heat pump at the
base of the air column. Remove that and the lapse rate drops to
zero and then inverts, as it does over Polar Regions during winter
and elsewhere during cold winter nights. Such inversions would be
far more frequent without the atmospheric GHGs that reduce
overnight cooling and diurnal variations in surface temperature.
Whereas the moist adiabatic lapse rate is ~5.5K/km, Postma confuses
this with the average environmental lapse rate (~6.5K/km): The wet,
or more commonly known as the normal or globally averaged lapse
rate, can be derived from the result of Equation (3) and the value
of the average atmospheric water vapour concentration at the
surface of the Earth. Water vapour concentration at the surface of
the Earth varies between 1% and 4% by volume [11], so an average
value for the volume concentration can be taken as 2.5%. (p. 8)
Wikipedia, his source [11], states that water vapour is typically
1%-4% at surface. Its a long bow to say that the average value is
therefore 2.5%. Postma continues: For an ideal gas, the molar
concentration is the same as the volume concentration . . . Apart
from the fact that water vapour is not an ideal gas, molar
concentration (Xm) is not the same as volume concentration (Xv) but
rather proportional to Xv. He then correctly determines that a
cubic meter of air at sea level with a water vapour content of 2.5%
by volume contains 0.0194kg of water. Wrongly assuming that this
uniformly diminishes with altitude to virtually zero at 10 km,
Postma says we can linearly interpolate the rate of condensation
per meter, as the air parcel rises, at 1.94 x 10-6 kg/m. (ibid) But
the height of the tropopause varies 9 across time and space, from
18km, the lapse rate is not constant and water vapour condenses out
nonlinearly as cloud layers, as explained in Wikipedia: An
unsaturated parcel of air of given temperature, altitude and
moisture content below that of the corresponding dewpoint cools at
the dry adiabatic lapse rate as altitude increases until the
dewpoint line for the given moisture content is intersected. As the
water vapor then starts condensing the air parcel subsequently
cools at the slower moist adiabatic lapse rate if the altitude
increases further. Postma then derives the wet rate of 6.24 K/km,
which is 4% less than the observed mean but nevertheless deemed
satisfactory given the average values used. (p. 9) He then works in
reverse starting from the observed environmental lapse rate to
derive the mean water vapour content at the surface: 2.29%, which
is 8.4% less than his original 2.5%. Using the lapse rate figure of
6.5K/km and the mean radiative layer height (derived from this
lapse rate and the observed values for Ts and Te ), Postma derives
IH from first principles without involving a GHE: If we combine the
above result of the natural temperature distribution (lapse rate)
of the atmosphere due to gravity, thermal heat capacity, and water
vapor condensation, with the fact that the average radiating layer
and temperature is found at ~5 km in altitude, we find that IH ~ 33
K (ibid) You can always get the answer you want when you start with
it! Only adiabatic lapse rates can be derived from first
principles; adiabatic appearing nowhere in Postmas paper. It
requires an atmosphere in hydrostatic equilibrium undisrupted by
wind turbulence, and no energy gain or loss by IR absorption or
emission. Postma ignores such non-adiabatic transfers of energy.
This reduces the lapse rate in the lower troposphere and increases
it at altitude, thus counteracting the latent heat effect there;
and so GHGs help to even out the lapse rate. In this formulation,
the GHE doesnt specifically have anything to do with actual heating
of GHGs or heating caused by backradiation from GHGs per se, but is
only about setting the radiative scale height H. However, with
increasing global surface temperature and increasing CO2
concentration (not necessarily causally related a priori), no
increase in the temperature scale height of the atmosphere has
actually been observed [13], thus putting into question the GHE
postulate itself, and the source of the warming. (ibid) His
citation [13] is to an article on The Missing Hotspot by David
Evans, who explains the greenhouse theory, accepts a GHE and admits
a faint or absent hotspot in his conclusion: Between a half and two
thirds of the temperature increases predicted by the IPCC are due
to their assumed theoretical water vapor feedback, which is also
responsible for the hotspot. Reducing the water vapor feedback in
the climate models in line with the faint or absent hotspot in the
observed warming pattern, while leaving the rest of their climate
model unchanged, cuts the temperature increases projected by the
IPCC by more than half. From four sources of radiosonde data,
Douglass et al (2007)8 likewise found that the tropical
mid-tropospheric warming trend during the satellite era (1979-2004)
was modest (~0.1C/decade) and less than a third of the mean
projected by 22 CGCM models. They did find a greater warming trend
at 8-10km than at 3-6km, but it was greater still at the surface
(Fig. 4). 10 Figure 4: Temperature trends (C/decade) over the
period 1979-2004 against pressure (altitude) for four radiosonde
results (HadAT2, IGRA, RATPAC & RAOBCORE = Observations)
compared to the average of 22 model predictions (solid red line)
2SE (lighter red lines) and two satellite MSU data sets (RSS and
UAH): the mean heights for T2lt and T2 being 2.5km and 6.1km
respectively. The surface temperature trend (Sfc) comes from
HadCRUT, GISS and GHCN. Source: Douglass et al, 2007 There are
several explanations for the surface warming of ~0.15C/decade:
either that it was primarily solar or that the surface temperature
record was inappropriately adjusted for urban heat and homogeneity,
as argued by Lindzen 9 and others,10 or perhaps both. Using data
from NCAR, NCEP and the European Centre for Medium-Range Weather
Forecasts, Santer et al (2003) 11 inferred that the tropopause had
risen several hundred metres since 1979; but this was contested by
Pielke and Chase (2004).12 The evidence for greenhouse warming last
century is neither strong nor entirely absent. Spencer and Braswell
(2010) 13 concluded from their study of clouds and feedbacks: It is
clear that the accurate diagnosis of shortterm feedbacks (let alone
longterm climate sensitivity) from observations of natural
fluctuations in the climate system is far from a solved problem.
Postma quotes Davies and Molloy (2012)14: the decadal change in
radiative forcing from CO2 is equal in magnitude (~0.28 W/m2) to a
change in effective cloud height of +19m *17+ . . . [and
postulates] If the cited cloud-height-forcing were linear, which we
might expect from Equations (1) to (3), then as an approximation an
effective cloud height of only 2.24 km would correspond to the 33K
forcing of the GHE, without needing to refer to any additional
backradiative heating mechanism. (p. 9-10) The +19m is less than
the variability described by Davies and Molloy: The linear trend is
44 22 m/decade and the interannual annual difference is 31 11 m
between the first and last years of the decade. The annual mean
height is measured with a sampling error of 8 m, which is less than
the observed interannual fluctuation in global cloud height for
most years. Moreover, clouds have different cooling/heating effects
in different parts of the atmosphere at different times of the day
in different parts of the world.15 Again, the picture is far more
complex than presented by Postma. 11 2. Development of the GHE via
Conservation of Energy Heat Flow Mechanics 2.1. The conservation of
heat energy ordinary differential equation Pages 11-18 are taken up
with heat-flow equations and time-lags in response rates at various
depths of Earths surface at two time constant tau (t) values
(0.05x105 and 4x105): The t values therein would correspond, if
modeling (sic) a sandy surface and soil of specific heat Cp = 800
J/kg/K [23], to masses of 6.25kg and 500kg, which equate to
square-meter soil columns of approximately 4mm and 31cm deep, given
a soil density of 1600 kg/m3 *23+. (p. 14) The various equations
are nicely solved and graphed using Matlab. This is straightforward
and uncontentious. My only quibble would be the use of an
emissivity of 0.7 in the Matlab script (Appendix D, p. 61) to
produce Figure 4 (p. 18). Postma bases this on Kirchhoffs Law, but
the terrestrial emission spectrum is quite different from the solar
absorption spectrum; and his albedo of 0.3 used in the Matlab
script does not pertain to the surface either. 2.3. The
conservation of heat-energy ODE and the greenhouse effect Page 19:
We note that, in typical treatments of the mechanism and physics of
the GHE, greenhouse warming is proportional to the surface output
flux because some fraction of that flux is absorbed into the
atmosphere and then emitted and/or scattered back to the surface,
which thus causes further heating. This is the so-called
back-radiation formulation (see Appendix H for a sample list of
quotation references adhering to the back-radiation mechanism of
the GHE), and it is functionally distinct from the formulation
discussed earlier in this report. So if from Equation (11) C(t)=
eoT4, where is the fraction of output flux which is kept from
exiting the system and/or returned to the surface thus causing the
greenhouse effect, we can just write t
= F in + C (t) (1 )eoT4 (W/ m2) (15) and where C(t) is no longer
a term which can represent the greenhouse effect, but is kept for
generality. In this formulation, the greenhouse effect as the gamma
term has the same effect as emissivity. However, the bulk of the
atmosphere is actually very stable in temperature, so the (1 ) term
could be removed and another constant term such as G0 could be
added to represent greenhouse effect heating. . . . So let us just
write t
= F in + GO (1 )eoT4 (W/ m2) (16) and then we can explore the
effects of using either G0 or in a numerical solution to get an
idea of how the greenhouse effect affects the heat flow balance.
Instead of removing (1 ), as he said he could, Postma removed C(t)
and replaced that with G0. There thus appears to be a contradiction
between his text and his revised formula [16]. He had defined C(t)
on page 13: C(t) is literally a climate term which could be either
positive or negative (adding heat or taking heat away) in total, or
composed of several unique contributions depending on if there is
an additional heat source such as the greenhouse effect, or
chemical and geologic sources etc., or an active cooling mechanism
such as that caused by wind. So, in removing C(t) he removed any
adjustment for heat loss by thermals and evaporation, and replaced
it with a second additive greenhouse variable in his formula [16].
Little wonder then that Postma obtained such strong temperature
responses when he used the KT97 value of 324 W/m2 for 12 G0,
illustrated in his Figure 5; and the Jacob (1999) value of 0.77 for
in his Figure 6; both shown on page 21 and discussed on page 22
(and reproduced below). If you factor in the KT97 backradiation of
324 W/m2, you also need to factor in the KT97 energy losses for
thermals (24 W/m2) and evaporation (78 W/m2). Indeed, you need to
subtract multiples of the combined global mean (~102 W/m2) for peak
evaporation and thermals at or shortly after zenith insolation,
whereas the GHE input remains constant. Figure 5: Temperature
responses with and without G0 term for two values of tau. The value
for G0 is explained in the text. Figure 6: Temperature responses
with and without gamma term for two values of tau. The value for is
explained in the text. Note that Postmas temperature response to
=0.77 is even greater than that to G0=324 W/m2. Had he plugged both
values (for G0 and ) simultaneously into his formula [16], which it
permits, he might have produced a Venus-like temperature! On page
28, he links his fictitious formula [16] to papers by Smith [2],
Kiehl and Trenberth [25] and others. But you wont find any such
formula there. 13 3. Discussion of Data and Collection 3.1. Raw
data Postma describes the half-hourly monitoring of air and ground
temperature and insolation over two days (21-22 June, 2012) up by
Carl Brehmer at Chino Valley in Arizona at latitude 34.8N and
altitude 4,701ft (1,433m). To monitor insolation, he used an Apogee
model MP-200 pyranometer, which measures wavelengths 280-2800nm
with an error of 3000nm). The air temperature and humidity were
monitored using an EasyLog model EL-USB-2 and the ground
temperature with a thermocouple and EasyLog model EL-USB-1. Whereas
Postma says: Day-time-high air temperatures are typically observed
approximately 3 hours after the solar noon, (p. 15) Brehmers peak
temperature occurred at 1.30pm on both days. The raw data is
tabulated in Postmas Appendix F (pp. 64-66) and plotted in his
Figure 7, reproduced below: Figure 7: Plot of raw measurement data
of insolation and ground and air temperatures. Data analysis is
found in a later section. 3.2. Preliminary data analysis The
measured maximum insolations from day 1 and 2 were 1060 W/m2 and
1052 W/m2, respectively, while the calculated TOA flux was 1291
W/m2 for both days. . . . Averaging the maximum flux values results
in an extinction of . . . 0.182 or 18.2%. The calculated TOA flux
was then linearly scaled down to reflect this value, and the
comparison to the measured insolation is seen in Figure 8, below.
(p. 24) 14 Figure 8: Plot of calculated & measured insolation
curves, showing extinction. Carl Brehmer measured the surface
reflectivity over 12 hours on June 13, 2012, by turning the
pyranometer upside-down and registering the value of reflected
short-wave radiation; the results can be found in Appendix G, and
are plotted in Figure 9 and Figure 10, and the measurements have an
average value of o ~ 0.26 . (p. 26) The albedo actually varied from
about 3.0 at sunrise and sunset (0) to 2.2 at midday (80). I have
no problems with Postmas presentation of Brehmers study thus far.
3.3. Comparison of the postulate of the greenhouse effect to
empirical data Our surface thermocouple was attached directly to
the ground surface and measured the rise and fall in its
temperature throughout the day; if the greenhouse effect is present
and the sky clear so that there are no confounding factors from
clouds etc. - all you have is the pure insolation and straight
greenhouse effect - then the temperature generated upon the surface
has to rise above that provided by solar insolation alone,
otherwise we lose the basis for the greenhouse effect postulate in
the first place. In the next section we discuss an even easier way
to test for this, but see Figure 11 below. (p. 28, emphasis mine)
Figure 11: No greenhouse effect is observed in empirical data. 15
In Figure 11, we have taken the measured solar insolation values
and converted them to their temperature-forcing value (factored for
albedo), and plotted that against the ground temperature and air
temperature. As can be seen, the ground temperature does not exceed
the temperature of the solar insolation. This is impossible given
the conditions of Equation (16) with either formulation of the
greenhouse effect heating term . . . (p. 29) I cant fault the maths
and admit that Postmas argument looks impressive at first glance;
but he forgets what he said on pages 15 and 16 when claiming there
are no confounding factors from clouds etc. - all you have is the
pure insolation and straight greenhouse effect. On page 15, he
states: The natural cooling effects of the air due to convection
and wind, which is driven by the temperature generated upon the
ground . . . and that temperature on the ground on Day 1 went to a
scorching 345K (72C), which was 33.5K warmer than the air 1.5m
above it, and 31.5K warmer on Day 2. Thermals (conduction and
convection) would have had a major cooling effect on that ground. I
suspect that the slightly lower temperatures (for both air and
ground) on Day 2 related to increased wind and conductive cooling,
but the wind speed was unfortunately not measured; nor were any
measures taken to limit wind or convective cooling. Postma
rediscovers this air-conduction on page 48, where he approvingly
quotes Doug Cotton: However, in the case of the surface /
atmosphere interface, at least 70% of heat transfer from the
surface to the atmosphere is non-radiative transfer. And on page
49, Postma states: The atmosphere is heated . . . mostly by contact
with the ground surface . . . GHE-deniers extol non-radiative heat
loss when it suits, but quickly and conveniently forget about it
when it doesnt! With a thermal conductivity for air of 0.024 W/m.K,
we would need to know the air temperature much closer than 1.5m
above the ground to calculate the conductive heat loss from a
surface at 345K. Using the KT97 value of 24 W/m2 for thermals
averaged over the globe, zenith insolation would be expected to
produce four times that, and even more with a ground temperature of
72C. So there could be well over 100 W/m2 of GHE, neutralised by
conduction / convection, right there in Brehmers data. Moreover,
Postma ignores conduction to subsoil. On page 16, he states: Solar
forcing acts directly only on the top few millimeters of surface
soil itself . . . and this is where the incoming short wave radiant
energy performs work and raises the temperature. This heat energy
will then conduct its way down into the subsurface until it merges
with the geothermal temperature at a depth of somewhere around,
say, 5 to 10 meters and temperature of approximately 5C to 10C. But
he apparently forgot about this when interpreting his Figure 11. On
page 30, he reports Carl Brehmer checking the soil temperature on
28 August (after several months of summer) and finding it to be 25C
(298K) at a depth of 84cm, with a diurnal temperature range of just
0.11C. From his Figure 4 (which has aforementioned problems), it is
likely that the temperature at this depth on 21-22 June was several
degrees cooler (i.e. 22-23C). So the temperature difference from
the surface to 84cm on 21 June could have been ~49K. We dont know
enough about the nature, density and moisture content of Brehmers
soil to accurately calculate conductive heat loss; but if we accept
a thermal conductivity of ~0.9W/m.K for dry sandy loam,16 the
conductive loss would be:
= ~53 W/m2 So we now have at least 150 W/m2 of GHE, neutralised
by conduction to air and soil, and probably a great deal more.
Furthermore, the peak surface temperature was 45-50C warmer than
soil 84cm 16 below, whereas the overnight surface minimum was just
5-8C cooler than the subsoil at 84cm. The peak surface cooling
temperature gradient was thus 6-10 times the peak surface warming
gradient from below, thus suggesting additional energy input from
above. The ground temperature on Day 1 was above the
albedo-corrected insolation temperature at all times other than at
the very peak. The increasing ground temperature in the early
morning could only be coming from above; and although the air
temperature warmed faster than ground temperature soon after
sunrise on both days, this could not convectively warm the ground
beneath it (as Postma aptly points out on page 34). Rather, as the
sun-warmed air stopped cooling the surface, atmospheric radiation
reinforced the weak insolation and so the ground temperature rose
well ahead of the insolation temperature, as shown in Figure 11.
When the ground temperature peaked at 72C, solar radiation received
exactly equalled radiation emitted, and therefore heat lost by
conduction (above and below) had to exactly equal thermal energy
gained from absorbed atmospheric radiation. Brehmers data
demonstrates very nicely that, without any atmospheric input of
energy there is ipso facto no spare energy for conduction (up or
down) and therefore no heat storage. You cant have one without the
other. If there was no atmospheric input, there could be no
conductive loss, even at peak insolation. GHE-deniers thus have to
deny (or conveniently ignore) conduction when interpreting Figure
11. Postma also ignored the effect of humidity and altitude on the
greenhouse effect at Chino Valley in Arizona. Brehmer recorded a
relative humidity of just 2.5% at peak insolation when air
temperature was 311K. The water vapour content at this altitude and
temperature was therefore only about 0.17% by volume. This is just
6.8% of the global average of 0.0194kg/m3 calculated by Postma; and
since the height of the troposphere is 15% less at 1433m elevation,
the total tropospheric water vapour (the dominant GHG) above
Brehmers monitoring station was barely 6% of Postmas global
average. The GHE at Chino Valley in June would thus be
significantly less than the global average, but still sufficient to
clearly show itself in Brehmers data. Rather than disproving the
GHE, therefore, Brehmers observations very nicely demonstrate it.
3.4. The back-radiation/glass greenhouse justification for the GHE
I have no problem with Postmas description of how greenhouses
actually work or his criticism of simplistic explanations of the
GHE (in Appendix H), or even with his assertion on page 32: If
back-radiation augments the warming that sunlight provides, as
alleged in the references and quotations in Appendix H and by the
heat-flow equation developed earlier in this report, then the
atmospheric GHE should be able to generate higher temperature than
real-time insolation can provide, even at its maximum. To this
author's knowledge, however, this has never been demonstrated for a
greenhouse, let alone the actual atmosphere. In his heat-flow
equations developed earlier, however, Postma did not correct for
the absorption of solar IR by glass or GHGs. Because of the reduced
transmittance of solar IR, daytime experiments with glass have not
confirmed any GHE; but I am unaware of any night-time studies of
cooling rates. I therefore propose the following experiment: 17
Overnight Greenhouse Experiment Each of four identical white
Styrofoam boxes (Fig. 12) would be filled as follows: - Bottom 1/3
with dry river-sand (equal quantities for thermal mass, and a
thermocouple placed above it at the centre) - Middle 1/3 with dry
air (and covered with a thin IR-transparent film) - Top 1/3 with
experimental Gas (containing a sealed water reservoir in one
corner, a thermocouple suspended as shown and covered with the same
IR-transparent film) Figure 12: Depiction of control and
experimental boxes for 3-day GHE experiment All boxes would slope
slightly towards the corner with the water reservoir so that
condensation would run into the open reservoir in the water vapour
box (# 3 below). The Gas in the upper chamber of each box would be:
1. Control Box: - Ambient air of low humidity 2. Pure CO2:
introduced from a gas cylinder through a valve in the side of the
box and vented at the top until more than full and the valve closed
3. Water vapour:- saturated air and OPEN water reservoir 4.
Greenhouse:- Ambient air of same low humidity as control box with
IR-absorbing glass on top of IR-transparent film The boxes would be
simultaneously placed close to each other, but separated, in a
uniformly sun-exposed area for three days (72 hours) during the
Australian summer, during which temperatures would be
simultaneously recorded at 2-hourly intervals from digital
thermometers connected to all 8 thermocouples and plotted against
time. The fine details of this concept need clarification and
elaboration. Now, back to Postmas paper: To test for a GHE at peak
insolation, Postma proposes a simple experiment using black paper
(Bristol board) with a thermocouple on top of it. He suggests
putting it on top of a stack of sheets to help insulate against the
surface contact, thus acknowledging that this paper has poor
thermal conductivity. So the thermocouple would be heated more by
direct sunlight than by the paper, and his discussed
absorptivity/emissivity of the paper is almost irrelevant. He does
at least advise a wind-break to limit conductive loss. Pity Brehmer
didnt do this. 18 Postma concludes section three by likening
radiation to conduction and by misrepresenting adherents of the
GHE: Now, it is interesting to note that physics has never
considered a back-heating term from back-conduction, in that the
heat from the atmosphere, being of a cooler temperature but having
been gained from the surface originally, is never thought to
sensibly return to the surface again and thus further increase its
temperature, or alternatively, to cause an increase in temperature
due to the conductive resistance from the atmosphere. This is only
a scheme that adherents of the GHE seem to propose for radiation
when they suggest that back-radiative heating, or alternatively
sometimes called back-radiative resistance, does cause such a
temperature increase, with their necessary justification being
postulated that radiation doesnt need to follow the Laws of
Thermodynamics in the same way we expect of sensible transfer. This
is of course rather doubtful. (p. 34) That energy transfer by
radiation is fundamentally different from sensible heat transfer by
conduction is very basic physics. Sound proponents of the GHE
clearly differentiate the two and never say that backradiation on
its own heats Earths surface, or that it contravenes any Laws of
Thermodynamics. Indeed, it is the GHE-deniers who ignore the first
law of thermodynamics when asserting that the electromagnetic
energy in backradiation has no thermal effect on Earths surface, or
else deny Kirchhoffs Law by claiming that those wavelengths are not
absorbed. This is a case of the pot calling the kettle black. 19 4.
The Sun and Global Energy 4.1. The sun heats the Earth? Is it
possible that the Sun can heat the Earth all by itself, or does the
atmosphere provide twice as much heating energy as the Sun provides
as per the K&T Global Energy Budget *25+ as supported by the
IPCC and believed by all supporters of the GHE? (p. 35) This (twice
as much) is not quite true for the KT97 budget, but it is for the
revised energy budget of Trenberth et al 2009. I have discussed
problems with these energy budgets in my critique of Slaying the
Sky Dragon. What Postma overlooks is that the energy in downwelling
atmospheric radiation is derived not only from terrestrial IR
radiation, but also from absorbed solar radiation plus convected
sensible and latent heat of evaporation/condensation. These
processes cool Earths surface by day and retard its cooling by
night. Postma spends the next five pages or so calculating the
prodigious quantities of sensible and latent heat in the oceans and
atmosphere, concluding: The latent heat component being on the
order of half of the total energy for water at 13C, means that
there will be a significant barrier to cooling below 0C as the
current circulates through the poles, keeping these regions much
warmer than they would otherwise be. This of course will skew-high
the characterization of the average global surface temperature and
thus provide an interpreted appearance of a GHE when there actually
is none. (p. 39) He doesnt do the maths, however, to show how the
heat got there or stays there without any assistance from a GHE. As
we saw earlier, the global mean temperature would be only 5C
without the GHE. Postma merely postulates sola solar and presents
no evidence other than his rudimentary model (on p. 43). Of course
the sun can heat the sunlit surface all by itself, but not enough
for heat storage, and it is powerless at night. Brehmers data
demonstrates very nicely that heat storage is impossible without a
GHE. Of course the atmosphere doesnt generate heat (except for
latent heat), but it slows the radiative losses from Earths surface
via clouds reflecting IR and via GHGs absorbing and re-radiating
some of it back to the surface. It thus helps to preserve the heat
generated by insolation in much the same way as a thermos keeps
your coffee warm. 20 5. Conclusion 5.1. The fraud of simple-minded
mathematics and sense-perception This is essentially a reiteration
of earlier arguments together with some sophistry to dance around
radiation, conduction and the first law of thermodynamics. Whereas
in radiation, electromagnetic (EM) energy is transmitted in both
directions between two separated sources, in conduction, thermal
energy flows one way as heat between two contacting bodies or
regions with different temperatures. Whereas there is a net
radiative transfer of EM energy from the warmer radiating entity to
the cooler one, Postma states: The two-way net transfer postulate
simply cannot work because it leads to the possibility that
radiation from a colder source can warm up a warmer object. (p. 47)
You dont reject sound physics simply because some people
misinterpret it. He then puts the Claes Johnson twist on the same
concept: Johnson actually . . . explains that EM waves/photons are
two-way, but the heat transfer mediated by EM waves/photons is
one-way. (ibid) In other words, there is indeed a two-way net
transfer of EM energy with a net gain by the cooler surface and net
loss by the warmer one. Postma then quotes Doug Cotton before
presenting his own argument on atmospheric radiation: We cannot
distinguish certain parcels of energy for other equal parcels of
energy exchanged in the same location, as it is equivalent to no
change having occurred at all. The only thing we can detect is that
when radiant energy of sufficient power is absorbed, it will induce
an increase in temperature until equilibrium is achieved. We know
that the area of the warmer Plank curve above that of the cooler
curve must be involved and be responsible for the heat transfer and
temperature increase, but the mutually corresponding areas of the
Plank curves for the two bodys emissions either may, or may not, be
exchanged and have the same effect which is no effect. The cool
portion of the radiation may or may not travel between the bodies
and be exchanged, and it really doesnt matter which option occurs
because they are indistinguishable from each other. (p. 49,
emphasis mine) Well, it matters a great deal if one of the bodies
is radiatively NOT THERE at all. Outer space is not cold, but
neither is it warm. It supplies almost no background radiation and
provides no barrier at all to radiative cooling. Without
IR-emitting gases in the atmosphere, the surface would receive no
cool portion of its radiation spectrum, all terrestrial radiation
would be lost to space and the surface would therefore cool much
faster, especially at night. Whereas the solar spectrum is quite
different from Earths, with very little IR overlap, because of the
vastly different temperatures, there is relatively very little
difference between Earths surface and its atmosphere. According to
Kirchhoffs Law, therefore, the surface will absorb all atmospheric
IR it wont reflect any of it. And the first law of thermodynamics
demands that that EM energy does not simply vanish when absorbed,
but is converted to thermal energy. Of course that cant warm a
surface that is losing energy faster than it is receiving it, but
it sure reduces the net loss and thus the rate of cooling. The
outer layer of a thermos cant warm your coffee, but reflects almost
the same EM energy as it receives. Does that mean it has no effect
or that it really doesnt matter? Take it away, then, and see how
long your coffee stays hot! If you dont believe that background
radiation from cooler sources makes any difference, do the
following simple experiment. Hold one hand about 5cm above a
kitchen bench at room temperature (about 298K or ~10C below that of
your hand) and the other hand about 5cm above a block of ice (273K)
a little larger than your hand and placed on a corner of the table
so that the cooled air around it can easily descend. Your hand
above the ice will soon feel cooler because it 21 receives less
background radiation than the hand above the bench. If you now
replace the ice with a bowl of liquid nitrogen (at 77K) your hand
will soon feel even colder because it is receiving even less
background radiation. If you want to be objective, attach a
thermocouple to your hand and record the temperature changes.
Regardless of its intensity or wavelength, background radiation
always matters, simply because it is there. We are so used to it
that we only become aware of it when it isnt there. If you could
expose your naked body to space, you would lose about 500 W/m2 (or
~1,000W for the average man) and cool very rapidly. Even an
insulating space suit has to be warmed. Without GHGs, Earths naked
surface would radiate 390 W/m2 directly to space and likewise cool
more rapidly, especially at night. Postma nevertheless points out
that: Cooling at the surface is enhanced by the atmosphere during
both day and night, rather than retarded. The top 10 meters or so
of a square meter column of soil holds more heat, and holds it at a
higher temperature, than the entire 10,000 kg of atmosphere going
from the surface to outer space. (p. 50) Yes, the atmosphere does
conductively cool the ground by day and to a much lesser extent at
night. As Brehmers data shows, the temperature difference at night
is very small and often reverses for a short time after sunrise.
But radiative energy transfer is not conductive; and besides,
atmospheric radiation does not warm the surface at night, but
merely retards its radiative cooling. As scientists, we need to be
careful in distinguishing radiation from conduction, EM energy
transmission from heat flow and warming from reduced cooling. These
are often confused on both sides of the GHE-debate. Once we get the
terminology right and consistently clarify our usage of it, we can
begin meaningful discussions. 5.2. A Note on the Human Mind This is
more about philosophy than science. In matters of science, we need
to let the evidence and the reasoning shape the philosophy, not the
reverse. We need to first get the science right. This is the only
point in the entire critique (apart from my introduction) to which
Postma responded: This represents the typically illiterate state of
mind of most so-called scientists today. Where does science come
from? Science comes from philosophy! This anti-intellectual,
a-logical, materialist edifice of philosophically illiterate
post-modern science is precisely why, presumably with a perfectly
straight face and totally unawares, that so-called scientists can
state that the atmospheric GHE causes heating but is impossible to
observe because the atmosphere is such a strong coolant(!). Yes,
the flat-earth notion came from philosophy, but science turned that
on its head. Notions of the cause of melancholia and blood-letting
practices also came from the philosophy about four humours, but
science has thankfully changed our philosophy. The question is
whether Postma will permit science to shape his philosophy. I will
let the reader decide whether his last sentence is an accurate
portrayal of my critique of his paper, or a rhetorical sophism to
hide his fundamental failure to factor conduction and convection
into his formula 16 and Carl Brehmers experiment. I will also let
the reader decide whether Postma has demonstrated the absence of a
GHE or otherwise. Postscript 2.1.13 Empirical evidence for a
greenhouse effect is provided by Carl Brehmer and Joe Postma, in a
discussion paper purporting to show the Absence of a Measureable
Greenhouse Effect, found at:
http://principia-scientific.org/publications/Absence_Measureable_Greenhouse_Effect.pdf
22 Carl Brehmer monitored insolation, ground and air temperature
every half-hour in June 2012 at Chino Valley in Arizona, and Joe
plotted his data for June 21 and 22 (Days 1 and 2 resp.) in figure
11. This shows that the ground temperature exceeded the insolation
temperature (corrected for albedo) for the whole of Day 1, except
for a brief period at peak insolation, when they both reached 345K.
Joe interpreted this as evidence that there was no additional
warming from atmospheric radiation or GHE. But he completely
overlooked conduction (fancy that!) both to the atmosphere and to
the subsoil. Evaporative cooling would have been negligible in that
arid location. From the limited data available, I estimated
conductive losses at the surface to exceed 150W/m2 at 345K. The
only possible source of extra energy for this conductive loss
(additional to the radiative loss calculated from the S-B equation
at 345K) is atmospheric radiation. This is less than half
Trenberths 333W/m2 (2009 Energy Budget), but still very
significant. It would be lower than the average given the altitude
(4,701 ft) and very dry air over Brehmers monitoring station.
Rather than acknowledging his mistake, Joe Postma called my
critique a joke, and stated: Youre not offering up mistakes, youre
offering obfuscations. All that exists anymore are semantic word
arguments for what people imagine and want it to do. Wes,
conduction is not an active cooling force like you find from a
refrigeration pump cycle. Conduction is simply the spreading out of
heat energy gained from some source, it doesnt actively cause
cooling. . . . Youre saying atmospheric radiation, from a colder
atmosphere, conducted into the sub-surface. First, radiation doesnt
conduct . . Heat flows from hot to cool automatically and this
doesnt require sustained input. . . . Conduction is not an active
cooling process. In this case conduction is a natural flow from hot
to cool given the solar input which heats the surface. Conduction
here is not the introduction of cold material to a warmer location.
Long-wave from the atmosphere can in no way, shape, or form, induce
the same or similar heating action as the short-wave solar input. I
will let others judge who is obfuscating and using semantics. Joe
would have us believe that passive conduction doesnt cool the
surface or require sustained energy input! Anyone who looks at Joes
figure 11 will see that the surface is warmer than it should be
(from insolation alone) for almost the entire Day 1, especially as
the sun sinks and the (extra) stored thermal energy in the subsoil
returns to the surface. Had Joe thought about this as a scientist,
instead of as a sophist, he might have considered surface
emissivity. With an emissivity of less than 1, the ground would
lose less radiation than indicated by its temperature, and so there
might be some spare energy for conduction, as well as for
radiation. Perhaps Carl might want to do some further work on this
in order to more accurately quantify the atmospheric radiative
energy required to meet the conductive losses at the surface. 23
References: 1 Donohoe, A. and D.S. Battisti, 2011: Atmospheric and
Surface Contributions to Planetary Albedo. Journal of Climate, 24.
2 Pidwirny, Michael (Lead Author); Dagmar Budikova (Topic Editor).
2007. Atmospheric effects on incoming solar radiation. In:
Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.:
Environmental Information Coalition, National Council for Science
and the Environment). 3 Haigh, J. D. 2007: The Sun and the Earths
Climate" 5.1 Absorption of solar spectral radiation by the
atmosphere http://www.livingreviews.org/lrsp-2007-2 4 Solomon, S.,
Portmann, R. W., Sanders, R. W. and Daniel, J. S. 1998: Absorption
of solar radiation by water vapor, oxygen, and related collision
pairs in the Earth's atmosphere, J. Geophys. Res., 103(D4),
38473858, doi:10.1029/97JD03285.
http://www.agu.org/pubs/crossref/1998/97JD03285.shtml 5 Wang, K.,
Liang, S. and Dickenson, R. 2009: Clear Sky Visibility Has
Decreased over Land Globally from 1973 to 2007 Science 323:
1468-1470 [DOI: 10.1126/science.1167549
http://www.sciencedaily.com/releases/2009/03/090312140850.htm 6
Kim, D., and V. Ramanathan, 2008: Solar radiation and radiative
forcing due to aerosols and clouds. J. Geophys. Res., 113, D02203,
doi:10.1029/2007JD008434. 7 Hansen, J. et al. 1981: Climate Impact
of Increasing Atmospheric Carbon Dioxide. Science, 213(4511). 8
Douglass, D. H., Christy, J. R., Pearson, B. D. and Singer, S. F.
2007: A comparison of tropical temperature trends with model
predictions. International Journal of Climatology: DOI.
10.1002/joc.1651. 9 Lindzen, R.S. 2007: Taking greenhouse warming
seriously. Energy and Environment, 18: 937-950. 10 Klotzbach, P. J.
et al 2009:, An alternative explanation for differential
temperature trends at the surface and in the lower troposphere, J.
Geophys. Res., 114, D21102,doi:10.1029/2009JD011841. 11 Santer, B.
D., Wehner, M. F., Wigley, T. M. L. et al. 2003: Contributions of
Anthropogenic and Natural Forcing to Recent Tropopause Height
Changes. Science Vol. 301. no. 5632, pp. 479 483 DOI:
10.1126/science.1084123 12 Pielke, R. Sr., Chase, T. 2004: Comment
on Contributions of Anthropogenic and Natural Forcing to Recent
Tropopause Height Changes. Science 19 March 2004: Vol. 303. no.
5665, p. 1771 DOI: 10.1126/science.1090986 13 Spencer, R. W., and
Braswell, W. D. 2010: On the diagnosis of radiative feedback in the
presence of unknown radiative forcing, Journal of Geophysical
Research, 115, D16109, doi:10.1029/2009JD013371.
http://www.drroyspencer.com/wp-content/uploads/Spencer-Braswell-JGR-2010.pdf
14 Davies, R. and M. Molloy (2012), Global cloud height
fluctuations measured by MISR on Terra from 2000 to 2010, Geophys.
Res. Lett., 39, L03701, doi:10.1029/2011GL050506. 15 Allan, R. P.
2011: Combining satellite data and models to estimate cloud
radiative effect at the surface and in the atmosphere. Meteorol.
Appl. 18: 324333
http://www.met.reading.ac.uk/~sgs02rpa/PAPERS/Allan11MA.pdf 16
Abu-Hamdeh, N. H. and Reeder, R. C. 2000: Soil Thermal
Conductivity: Effects of Density, Moisture, Salt Concentration, and
Organic Matter. Soil Sci. Soc. Am. J. 64:12851290 (2000).