Doug Cotton: Radiated Energy and the Second Law of Thermodynamics

Posted: March 13, 2012 by tallbloke in atmosphere, climate, Energy, Kindness, Ocean dynamics

I have been asked by Doug Cotton to draw attention to the paper he has written. I’m happy to do so, despite some personal reservations regarding some of the inferences drawn from observations. I request that all comments are polite, and kind-hearted. Everyone is learning about radiation, the process is ongoing.

Radiated Energy and the
     Second Law of Thermodynamics
Douglas Cotton, B.Sc., B.A., Dip. Bus. Admin
March 12, 2012


The transfer of thermal energy by radiation is discussed in the context of the Earth’s
surface and its atmosphere. When considering what happens as the Sun is warming
the surface each morning, it is noted that its radiation is being directed onto the land
surfaces and some distance below the surface of the oceans. So, additional radiation
supposedly transferring further thermal energy from the cooler atmosphere to the
warmer surface would violate the Second Law of Thermodynamics. This law must
apply (on a macro scale) between any two points at any particular time. An apparent
violation cannot be excused on the basis of “net” radiation, because “net” radiation has
no corresponding physical entity and is meaningless and useless for determining heat
flow in situations when other processes are also involved.

It may be deduced that none of the radiation from a cooler body (and only a portion of
the radiation from a warmer body) has any thermodynamic effect on the other body.
All such radiation from a cooler source is rejected in some way, and it can be deduced
that resonance and scattering occurs without any conversion to thermal energy. The
radiation continues in another direction until it strikes a cooler target, which could be
in space.

Furthermore, the stability of sub-surface temperatures will tend to maintain the
observed close thermal equilibrium at the interface between the surface and the
atmosphere. Hence other heat loss mechanisms are likely to adjust, in order to
compensate for any reduced radiation.

Some commonly raised questions are answered in the Appendix, where there is also
discussion of temperature trends and climate cycles, as well as counter arguments for several possible objections to matters raised herein.

Full pdf here

  1. Doug Cotton says:

    In Maxwell’s Theory of Heat on pages 244 & 245 he describes how a gas only absorbs radiation when it is cooler than the emitter. This is what Prof Claes Johnson has established computationally. It is the reason why energy in backradiation from a cooler atmosphere is not converted to thermal energy in a warmer surface, so there is no heat transfer. You can read Maxwell with these links p.244 and p.245

  2. Doug Cotton says:


    In response to a question about the article published today (to which I contributed) I will summarise what would happen in a hypothetical Earth with no water and an atmosphere of only nitrogen and oxygen, assumed not to radiate or absorb.

    If this were the case the Earth’s surface would receive more radiation during the day because there would be (virtually) no absorption of incident solar radiation. When you then apply S-B (using integration on a real-world spherical surface) the majority of the radiation would take place directly from the surface at these hotter temperatures.

    But there would still be an adiabatic lapse rate ensuring that the nitrogen and oxygen are much warmer at the base of the atmosphere than at the top, even if no energy flows in and out of the atmosphere. Thus is because an adiabatic lapse rate is just that – adiabatic – and so requires no energy input to maintain the temperature gradient. Thus the surface would not cool anywhere near as much as the Moon’s surface does at night. In fact, the surface temperature would be stabilised by conduction both from the atmosphere and the mass below the surface. There is no reason to believe its mean temperature would be much different, even though its temperature would vary more between day and night.

    In a nutshell, this is why the accusation that radiating gases produce a GHE and raise the mean surface temperature is all garbage.

    You can’t raise or lower the mean surface temperature significantly (within a few thousand years) without transferring an impossible amount of energy into or out of the whole Earth system, including all the mass beneath the crust, right down to the core.  

    That is the core of my argument.  

    See the big picture!

  3. Doug Cotton says:
    November 16, 2012 at 12:39 am
    In Maxwell’s Theory of Heat on pages 244 & 245 he describes how a gas only absorbs radiation when it is cooler than the emitter.

    Where precisely on those two pages does he say that?

  4. Doug Cotton says:

    As I will demonstrate below, the planet Venus provides an interesting example of what would be a major dilemma if one tried to apply the concepts which are used to construct the “standard” radiative greenhouse conjecture.

    You will be aware of how the IPCC and others claim that water vapour, carbon dioxide and other similar radiating gases send backradiation to the surface, and this backradiation supposedly slows the overall rate of cooling of the surface. Somehow, as a result, this is meant to raise the temperature of the surface by 33 degrees. This is the essence of the current description of the “Greenhouse Effect.”

    Does something similar happen on Venus? Many claim that it does.

    However, on Venus the “slowing of the cooling” is supposed to account for about 500 degrees, because that is about how much hotter the surface is than the equivalent radiating temperature of the whole planet.

    But the interesting thing is that, because the atmosphere on Venus is about 94 times the mass of the Earth’s atmosphere, scientists have been able to calculate that only about 2.5% of the Solar radiation at the top of the Venus atmosphere gets through to its surface. That amount would be roughly 10% of the mean radiative flux received at the Earth’s surface.

    Now the radiation received at the Earth’s surface warms it and causes some upwelling radiation, and that in turn leads to downwelling radiation. But obviously the latter could not have more energy than the original radiation reaching the surface.

    Even if the amount of radiation on Earth were able to raise the Earth’s surface by 33 degrees, how could 10% of that radiation raise the Venus temperature by 500 degrees?

    You see, on Earth it is not hard to understand, because we know that the Sun at noon can raise the surface temperature up to and above 288 K, and so we can accept that slowing of the cooling from a temperature higher than 288 K could lead to a mean of 288 K.

    But on Venus, there is no initial boost in temperature (caused by the Sun) that could raise the surface more than 500 degrees using only 10% of the radiative flux we receive on Earth.

    Yet, that is what the temperature is, so how does it get so hot on the Venus surface?

    An explanation, based on empirical results in scientific experiments, will follow in the next day or two when perhaps some readers may have made suggestions as to the mechanism involved.