Confusing Diabatic and Adiabatic Processes within the Climate Theory:

A Reply to Dr. Roy Spencer’s Blog Article “Giving Credit to Willis Eschenbach”

Ned Nikolov, Ph.D.

Physical Scientist

In a recent blog post, Dr. Roy Spencer at the University of Alabama at Huntsville attempted to criticize and dismiss the importance of our recent discovery about the physical nature of the atmospheric “Greenhouse effect” (Nikolov & Zeller 2017). I normally do not reply to blog articles, but this one reflects a fundamental generic confusion in the current climate theory that is worthwhile addressing for readership clarification. In his blog, Dr. Spencer demonstrated several misconceptions about our work that could be due to either not having read/understood our papers or perhaps an incomplete grasp of thermodynamics. The fact that Dr. Spencer cites a newspaper article about our research instead of the actual published paper may indicate a lack of familiarity with the technical details of our study. These are some key misrepresentations that I spotted in his article:

1. Dr. Spencer incorrectly referred to our main finding as a “theory” when, in fact, it is a discovery based on vetted NASA data extracted from numerous published studies. This empirical pressure-temperature (P-T) function emerged from reported NASA measurements in the process of Dimensional Analysis, which is an objective technique employed in classical physics to derive/extract physically meaningful relationships from observed data.

As discussed in our paper, the new interplanetary P-T relationship shows features of a possible heretofore unbeknown macro-scale physical law given its high accuracy, broad environmental range of validity, and statistical robustness. Hence, this relationship is not a coincidence and demands a theoretical explanation that we provide in the paper by comparing it to other well-known P-T physical relationships. Thus, our study is rather different from the work of Fourier (1827), where he conjecturally proposed what is now known as the atmospheric “Greenhouse” effect. His proposal was later accepted on faith by Arrhenius (1896) and Callendar (1938). These researchers were not able to distinguish between gas IR absorption measured in a laboratory and the surmised “radiant-heat trapping” in an open atmosphere, which has never been observed. The “Greenhouse” concept is an example of a “contrived theory” based on conjectures that requires proof (i.e. empirical verification), while ours is an empirical fact that begs for a theoretical interpretation. Dismissing an observed pattern such as our highly accurate cross-planetary P-T relationship using “theoretical” arguments is backward to the Standard Scientific Method. Yet, Dr. Spencer employed a misconstrued thought experiment suggested by Willis Eschenbach in Jan of 2012 as a tool to “disprove” our empirical findings published in a 2017 paper?! Such an approach only raises eyebrows, as it indicates an inability to distinguish facts from fiction. Furthermore, we have addressed the conceptual and math errors made by Willis Eschenbach in a reply dated Feb 9, 2012, which Dr. Spencer failed to mention in his critique.

2. Dr. Spencer did not consider the role of adiabatic processes in atmospheric dynamics that are complimentary to the well-understood diabatic heating by solar radiation. An adiabatic process alters the internal kinetic energy and temperature of a gaseous system without exchanging heat or matter with the surrounding environment. The change of internal energy in this process is solely due to a change of system’s internal pressure. The adiabatic process emerges from combining two fundamental laws of Thermodynamics: Conservation of Energy and the Ideal Gas Law! Since pressure is a force per unit area, it is intimately related to kinetic energy because, in gases, Kinetic Energy (Joule) = Pressure*Volume. The direct effect of pressure on temperature (i.e. the adiabatic heating & cooling) is evident in all thermodynamic systems. A classic example of a sustained global adiabatic thermal effect in the troposphere is the well-known decrease of temperature with altitude known as adiabatic lapse rate. It is caused by a temperature change (dT) with pressure and the pressure decrease (dP) with altitude (z), i.e. dT/dz = -(dT/dP)(dP/dz). The observed vertical pressure gradient is the core reason for the existence of a negative lapse rate in the troposphere. The magnitude of the actual lapse rate, however, depends on the strength of surface solar heating and other factors such as vertical moisture profiles. Many scientists (Dr. Spencer including) confuse the lapse-rate cause with factors controlling the lapse-rate magnitude. Other common examples of adiabatic heating in the atmosphere include Chinook winds, Santa Ana winds, and Sudden Stratospheric Warming. Air convection and cloud formation could not occur without the adiabatic cooling/heating experienced by rising/falling parcels of air as they move through tropospheric levels of various pressures. In fact, as pointed out in our paper, no thermodynamic system can possess kinetic energy and temperature above absolute zero without some form of pressure present. Even electromagnetic (EM) radiation has pressure! Thus, an EM flux commonly measured in W m-2 is basically a product of photon pressure (in Pascal, Pa) and the speed of light (m/s) when decomposed into its fundamental physical units, i.e. 1 W m-2 = 1 Pa*m/s. Disregarding adiabatic processes in a thermodynamic system such as the atmosphere is equivalent to ignoring (misunderstanding) half of the system’s behavior. Our analysis of NASA planetary data revealed that the Atmospheric Thermal Effect (currently known under the incorrect name “Greenhouse effect”) is a stable form of a macro-scale adiabatic heating caused by a permanent air compression at the surface that is independent of gaseous composition. This is illustrated in Fig. 4 of our paper reproduced below (the ratio T s /T na on the vertical axis quantifies the atmospheric thermal effect). This result is in full compliance/agreement with the classic Thermodynamic theory and does not violate any natural laws. Specifically, an adiabatic (pressure-induced) warming cannot violate the First Law of Thermodynamics as claimed by Dr. Spencer, because it is derived from that Law!

Figure 1. The Atmospheric Thermal Effect (ATE) expressed as a ratio of actual surface temperature (T s , K) to a ‘no-atmosphere’ surface temperature (T na , K) of planetary bodies plotted against surface atmospheric pressure (kPa) reveals a tight relationship across the Solar System (Fig. 4 in Nikolov & Zeller 2017).

3. As well as misunderstanding adiabatic processes, Dr Spencer overlooked a crucial new finding in our study: Atmospheric long-wave radiation is a manifestation (or byproduct) of the kinetic energy in the troposphere, rather than a cause for such energy. This is discussed on p. 14 of our paper:

As with any other gaseous system, the internal energy of the troposphere (measured in Joules), which gives rise to both air temperatures and long-wave radiation, is determined by the product Pressure*Volume. The pressure is set by atmospheric mass, Earth’s surface area and gravity, while the tropospheric volume is controlled by solar heating. The atmospheric volume varies with solar insolation/heating as indicated by the observed difference in tropopause heights between Equator and the Poles, while the surface air pressure is mostly independent of solar radiation and temperature. Dr. Spencer claims that our concept violated the First Law of Thermodynamics (Conservation of Energy), because our model does not consider atmospheric IR back radiation. First, it should be pointed out that an empirical model derived from measured data cannot violate Nature’s laws, because it reflects reality! The fact that our regression model accurately describes the global average surface temperatures of planetary bodies throughout the Solar System without explicitly considering long-wave IR radiative fluxes indicates that such fluxes are not a needed component for predicting global temperatures! That’s consistent with the notion that the IR back radiation is a consequence (result) of atmospheric temperatures. Secondly, viewing the IR back radiation as a separate energy source to the surface that augments the solar flux as done by Dr. Spencer in an effort to explain Earth’s elevated temperature above the Stefan-Boltzmann (S-B) “no-atmosphere” value is physically and methodologically incorrect for the following reason. According to the “Greenhouse” theory, the IR back radiation represents a wavelength-transformed solar flux (from short-waves to long-waves). Yet, it is also interpreted as a diabatic (external) energy source to the surface. This self-contradictory view leads to an inexplicable paradox. The solar radiation absorbed by the entire Earth-atmosphere system is ~240 W m-2. However, the average down-welling IR radiation in the lower troposphere is measured at 342 W m-2 while the IR flux emanating from the surface is ~398 W m-2 (see the 2013 IPCC AR5 energy-budget diagram).

If the Sun were the sole source of energy to the climate system as claimed by the “Greenhouse” theory, how could long-wave IR fluxes in the lower troposphere exceed the total absorbed solar flux by more than 40%? The discrepancy between short- and long-wave radiative fluxes becomes extreme on Venus: that planet only absorbs 65 W m-2 solar radiation due to a 90% cloud albedo, while its lower troposphere emits >15,200 W m-2 IR flux towards the surface! This paradox cannot be explained by a simple absorption and re-emission of solar radiation, because such a mechanism cannot elevate (especially in the presence of convection) the tropospheric internal kinetic energy above the net solar input as observed in reality. It’s also important to note that the re-radiation of IR energy is qualitatively different from and should not to be confused with reflection. Greenhouse gases do not reflect IR radiation! Therefore, trying to explain the down-welling IR flux and surface temperature diabatically, i.e. through radiative fluxes alone, leads to a conflict with the First Law of Thermodynamics, since such an explanation effectively creates energy out of thin air. Thus, it must be physically incorrect. Our discovery of the adiabatic nature of the Atmospheric Thermal Effect provides a new feasible way to explain the observed energy-flux paradox without violating Nature’s laws. Air pressure caused by gravity acting on the atmospheric mass enhances (by virtue of its force) the amount of solar energy absorbed directly or indirectly by the atmosphere. This adiabatic thermal enhancement is consistent with the First Law of Thermodynamics and evident in the general form of the semi-empirical Equation for calculating the average surface temperatures of rocky planets (T s ) derived in our paper, i.e.

T s = T na E a

where T na is the planet’s surface temperature in the absence of atmosphere (i.e. the S-B temperature value), and E a is the adiabatic atmospheric thermal enhancement quantifying the relative effect of pressure on temperature. For planetary bodies with no atmosphere, E a = 1.0. For bodies with an atmosphere, E a increases above 1.0 as a non-linear function of total pressure reaching 3.18 for Venus (the rocky planet with the most massive atmosphere in our Solar System). For Earth E a = 1.459 , which means that our atmosphere boosts Planet’s average surface temperature 45.9% above its S-B value.

4. Finally, Dr. Spencer confuses one’s ability to observe/measure IR back radiation with the correctness of one’s understanding about the role of that radiation in global climate and the Atmospheric Thermal Effect. No one denies the existence of long-wave radiative transfer and IR back radiation in the atmosphere, but its global meaning has been misinterpreted for nearly two centuries. Just as it was “obvious” to medieval scholars studying the movement of heavenly bodies that Earth was at the Center of the Universe, since all lit objects in the sky seem to revolve round us, so too it has been “obvious” to climate scientists for 190 years that the down-welling IR radiation was responsible for the warming effect of Earth’s atmosphere. It took a proper placing of Earth in the context of a cosmic continuum of climate drivers to discover that the IR back radiation was in fact a byproduct (an effect) of Sun’s diabatic heating and atmosphere’s adiabatic enhancement of the amount of absorbed solar energy.

In conclusion, the “radiative Greenhouse effect” does not exist. The atmosphere warms the surface thermodynamically through a form of adiabatic compression that only depends on total pressure. Adiabatic processes, although well understood in classical Thermodynamics, are not part of the current climate theory, which focuses almost exclusively on diabatic radiative processes. As a result of this conceptual bias, climate-science classes taught at Universities do not properly explain the direct effect of pressure as a force on the temperature of thermodynamic systems. Instead, pressure is only discussed as a factor affecting the atmospheric IR optical depth assumed to control surface temperature through a purported “trapping” of radiant heat, which is not observed in the open, convective atmosphere.

The above points are clearly explained in our 2017 paper. It is therefore puzzling why Dr. Spencer failed to grasp them assuming he had read the paper. Or maybe he hasn’t? The thought experiment proposed by Willis Eschenbach in 2012 (i.e. 5 years prior to the publication of our paper!) to “disprove” our findings has no basis in real physics and reflects a poor understanding of thermodynamics. While such a dismissive and indefensible position might be excusable for Mr. Eschenbach, who has no formal education in physical sciences, it is certainly inexcusable for Dr. Spencer to claim that our empirical results backed by vetted NASA data and fully explainable by adiabatic processes represent a “violation of the fundamental 1st Law of Thermodynamics: Conservation of Energy”.

My big question regarding the above debate is this: Why do some “climate skeptics” such as Dr. Roy Spencer, Anthony Watts and Wills Eschenbach go out of their way to defend a discombobulated 19th-Century theory, which is at the heart of the anthropogenic climate-change exaggerations that they claim to have been fighting against for decades? It makes no rational sense for skeptics to argue ad nauseam about marginal issues such as rates of warming or sea-level rise while vigorously protecting by all means the rotten core of a concept that allows the promotion of exaggerated claims about such issues to be made in the first place.