Heat Radiation is accomplished by propagating EM fields.
EM fields are Force fields, in fact the Electromagnetic Force is one of the four fundamental forces.
EM fields carry “Photon Energy”.
Photons have zero Mass.

Is it so surprising that opposing EM fields and corresponding Forces will only move the zero mass Photon energy in the direction of the larger force?

The “block of wood” analogy should be apparent except that, unlike a “block of wood”, a Photon has zero mass.

Hot objects produce a larger EM field (and force) than Cold objects so heat energy can only flow from Hot to Cold!….The direction of the larger force!

This is really what 2nd Law of Thermodynamics is fundamentally saying!

“Second Law of Thermodynamics: It is not possible for heat to flow from a colder body to a warmer body without any work having been done to accomplish this flow. Energy will not

flow spontaneously from a low temperature object to a higher temperature object.”

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html#c3

When you AGW’ers say that Heat can flow from Cold to Hot it’s like saying the “block of wood” will move in the direction of the weaker force!
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Electromagnetic Fields are Vector fields.
When opposing EM vector fields are summed, there can only be ONE resultant EM Vector Field.
The Magnitude will be (Larger Field – Smaller Field) and will always be in the direction of the Larger field.
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Measuring Back-Radiation:

1. Direct measurements require the detector to be cooled below the atmospheric temp.
2. Indirect measurements measure the loss of energy (eg.Thermistor) to the cooler atmosphere.
3. Solar Ovens (parabolic mirrors will concentrate solar and IR energy at a focal point) and should work at night if back radiation actually reached the Earth.

Black ball equations to work out the temperature of the earth without a atmosphere are not appropraite for the earth and ignore the moderating effect of the sea, which effectively controls the throughput of energy and the overall energy balance.

Do not attack people who question current scientific concesus (or dogma even), this kind of open thought is encouraged in other fields of science as it enables the advancemet of science, even if proven wrong, it helps support the alternative hypothesis. Remember, concesus is the last hiding place of bad sciece. If we always assumed current scientific understanding is right, we would still think tectonic drift is impossible.

Where is this 34 years coming from? I can already count 150 years of direct temperature measurements. And if you thrust temperature reconstructions, yan can go back to several centuries before now…

That’s a personal question. I trust science and scientific reconstructions, so I can go back to million years back. Don’t you?

Just to say it doesn’t make sense to take a few years, or even a decade, to discuss the evolution over a century.

And it doesn’t make sense to take 34 years for discussing the evolution of climate on Earth over a millenia.

The model was created in 2003. The paper shows, in order to close that kind of discussions, that models do predict long periods of seemingly flat temperatures, even decreasing temperatures, which in any case does not prevent the long-term trend to be positive. This particular example for example predicts a flat temperature over the 2000-2010 period. It even predicts a 20-year long flat temperature period during the 21st century – but nevertheless the trend is there.

Just to say it doesn’t make sense to take a few years, or even a decade, to discuss the evolution over a century.

Nasif “They don’t take into account that heat incoming from the Sun is transferred by conduction from the surface to the subsurface layers, where it is stored until the sun declines and the incidence of direct solar radiation disappears, this is, during nighttime”.

That would make a lot more sense than GHG activity since N2 and O2 make up 97% of the atmosphere.

I agree with Stephen’s article, except for the name he gives to the process, but my disagreement on how he’s labeled the effect has nothing to do with science.

The next statement has lifted some doubts about Stephen’s thesis:

“There is always a net loss of heat on a daily basis from atmosphere to space regardless of any atmospheric greenhouse effect. ”

This is true because every region of Earth alternates day and night every day; for example, when in meridian W 90 is noontime, it is midnight in meridian E 90. However, one cannot say that the sensible heat flux towards the outer space during daytime in any meridian is higher than during nighttime because the solar photon stream on the illuminated side induces the photon emission towards the surface. Nevertheless, the amount of photons induced towards the surface from the atmosphere is sensibly small and it is far lesser than the emission induced by the surface photon stream from the atmosphere towards the outer space on the dark side of the Earth. Nevertheless, the net loss of heat is given regardless any atmospheric warming effect. Earth is not a thermo.

As for conduction as the main heat transfer mode from the surface to the atmosphere, the assertion is supported by observation and experimentation. The radiation meassured in the atmophere during nighttime is not “downwelling” radiation, but upwelling radiation from the surface (land and oceans) which is captured by atmospheric gases by convection. I have made many meassurements with radiometers and I have never meassured any “downwelling” radiation.

The real process happens when the surface transfers energy towards the atmosphere by conduction, i.e. the surface is a conductive donator of energy, while the atmosphere takes the energy by convection, i.e. the atmosphere is convective acceptor and conveyor of energy. The effect is more evident when the ground is saturated, i.e. when it doesn’t absorb any more water.

Regarding the assertion on N2 and O2 like the main conductive “acceptors” of photons in the atmosphere, it’s enough with seeing the thermal conductivity coefficients (k) of N2 and O2, which is 0.02583 W/m K for N2, and 0.02658 W/m K for oxygen. In comparison, carbon dioxide k is 0.017 W/m K, which is lower than k of N2 and O2. On the other hand, k of water is 0.6 W/m K. So, it’s clear that water thermal conductivity is 9x higher than k of CO2.

However, the prevalence of water is more evident if we consider the free thermal convective coefficient (h obtained from |∆Q|/|A (∆T) (∆t)|) because h for water is 20 to 100 W/m^2 K at 300 K, while h for the dry mixture of air, under the same conditions, is 0.5 to 2.5 W/m^2 K. Thus, the convective maximum potential of water overwhelms by 40 times the dry air convective maximum potential, yet if one forces air convection with a fan (up to 30 W/m^2 K).

Concluding, I agree with Stephen on his assertion that the warming effect of the atmosphere is due to water in its three phases, not to air.

Nick…I have tried being polite with you because you seem to be a decent guy. RW is a nincompoop (a silly, foolish, or stupid person) and you’re beginning to insult my intelligence. Although I place no value in ego, I wont sit around and be talked down to by a mathematician who is seriously confused about physics. I have watched you arguing feedback with Jan Pompe and I know you have no idea what it is. Now you’re lecturing me on blackbody radiation.

The Sun approximates a blackbody radiator because it emits a broad specturm of energy which satisfies Planck’s function. The radiated energy is due to vibrating atoms, not optical depth. Optical depth may be a function of the gas and temperature but it is not the source of the broad-range of radiative emission frequencies.

Talk about babbling. Just Rabett’s coverage of Clausius and the 2nd Law reveals neither he nor any of his contributors have the slightest idea what the 2nd Law means. Listing Peirrehumbert, a geophysicist, as an expert source, is pure humour.

Rabett just doesn’t get the obvious. Energy supplied by the surface to heat the atmosphere is a LOSS OF ENERGY at the surface. Rabett is describing a positive feedback where an essential source of amplification is missing. That’s why G&T refered to the process as a perpetual motion machine: the process is creating energy that is not there.

Roy Spencer has addressed that in his latest blog, but I have to respectively disagree with Roy. he has pointed out that climate scientists have re-defined positive feedback and it’s actually a negative feedback. At least Roy admits that. People like Rabbett have no idea what is involved in feedback.

The loss of energy at the surface has to be made up before the surface can heat beyond the temperture it was heated by solar radiation. You cannot add solar radiation a second time to a quantity that represents a loss of surface heat. The solar radiation was used to heat the surface and part of that heat was used to heat the atmospheric GHG’s. The heat represented by the GHG’s is not an independent source that can be added to solar radiation. If anything, the back-radiation is only making up the losses that created it.

Rabbett is obviously confusing the heat contained in the water of clouds with atmospheric WV and CO2. Besides that, the GHG’s are far too rare to make a difference. Also, they are warmed by a different frequency spectrum than they emit at.

I certainly hope Rabbett doesn’t consider submitting that nonsense to a physics journal. I can see it being accepted by the Journal of Climate, but not a serious physics journal.

Nick…you’re talking like a mathematician. Who said N2 and O2 are not absorbing? They are absorbing energy from the surface through conduction and a process that carries the warmer air aloft. Radiation is only one form of heat transfer. The satellites measure tropospheric temperatures from O2. How does it get it’s heat? Please don’t tell me it gets it from GHG’s, which account for 1% of the atmosphere.

What makes more sense: that gases accounting for 97% of the atmosphere are involved in heating it, or that gases accounting for 1%? I know where I’m putting my money.

When I was taught weather theory in high school, I was taught that warm ‘air’ rises. No one mentioned warm GHG’s rising. I understand the basic theory of precipitation, that water vapour rises, condenses, and forms rain or snow. However, WV is a part of air, not a separate entity. It rises with the N2 and O2 when heated by the surface by conduction in the boundary layer.

I don’t know why you consider that babble.