Discussion of an Atmospheric Pressure Theory suggested by Patrice Poyet as a potential alternative explanation for current Global Warming, or as a potential reason to reject Anthropogenic Global Warming
You say you don’t have to provide an alternative theory for the recent temperature trends on Earth.
In fact, you have offered an alternative explanation for warming on Telluric planets (mostly composed of silicate rocks) (eg Mercury, Mars, Venus and Earth) quite recently.
It could perhaps be phrased as “it’s atmospheric pressure, irrespective of atmospheric composition, that is the main determinant of surface temperature, not the greenhouse effect, and because of this global warming on Earth is not significantly affected by greenhouse gas emissions from human activities”.
Before looking at supporting materials, there is immediately a question of logic and temporal context.
Timescales are not explicitly included in such a statement. This could be significant in attempts to reconcile what could be described as the “Atmospheric Pressure Theory” (APT) with the AGW theory.
If one driver of temperatures (eg the greenhouse effect, at decades to centuries) is having large effects in recent times and this is a very different timescale from those most relevant to other significant effects (eg atmospheric pressure, at geological timescales), then the statement of your theory above could be found to be:
The logical nature of the argument you seem to use is that because APT is a strong determinant of surface temperature (“the main driver”), CO2 must be an insignificant determinant of surface temperature. This does not logically follow in that way. They could both be strong determinants of temperature, but to differing degrees and at different times (or in different timescales, as mentioned already).
I’ll leave that thought with you, while we dive into more detail.
Let’s look at some material from your ebook. Some of the highlighting (eg emboldening or underlining) is mine, to better track what I think are the main points relevant to your explanation of what I’ve dubbed “APT” (Atmospheric Pressure Theory).
From page 40 of your ebook:
“H2O vapor is a much more important gas than CO2… The atmospheric pressure which determines the temperature on the ground… [and] … many other processes account for heat transfers and contribute to the Earth’s temperature.”
On page 41, under a heading “Temperature results from the Gravitational Lapse Rate [LR]”:
“… atmosphere of Venus was mainly made of carbon dioxide (96.5%) and … the ground pressure was 93 bar whereas the tenuous atmosphere of Mars was also mainly made of carbon dioxide (95.3%) but with a ground pressure of only 0.006 bar. Of course the difference of the ground temperature are striking: Mars’ surface temperatures may reach a high of about 20 °C (293 K; 68 °F) at noon, at the equator, and a low of about −153°C (120K; −243°F) at the poles whereas Venus is by far the hottest planet in the Solar System, with a mean surface temperature of 735 K (462°C; 863°F). Then it dawned on me rapidly, observing that the temperature on Earth drops when you go up in the mountains, that there was a direct relationship with the atmospheric pressure and that the composition of the atmosphere itself did not seem to play a major role… summarized by Wilde and Mulholland (2020) "We discuss how with knowledge of three simple meteorological parameters of tropopause elevation, tropopause temperature and lapse rate for each atmospheric cell, combined with the measurement of the area of that cell, the average global surface temperature can be calculated".
You further develop your thinking on page 42:
“Detailed meteorological considerations are not addressed because they go far beyond the scope of this section and are furthermore completely irrelevant as the emphasis is on understanding and obtaining an average global surface temperature, anywhere on Earth given the aforementioned parameters, and especially thanks to the notion of Lapse Rate (LR) … “
After some calculations, you state, on page 46:
“… I had guessed since I was a youngster and read Sneath (1970) it is well established that the average surface temperature does not result from radiative phenomena in thermal infrared but quite essentially from atmospheric pressure on Earth as on Venus (Sorokhtin et al., 2011)”
The reference is to Sorokhtin, O. G., Chilingar, G. V., and Sorokhtin, N. O., 2011. “Evolution of Earth and its Climate, Birth, Life and Death of Earth”
As an aside, in Sorokhtin et al (2014) “Do Increasing Contents of Methane and Carbon Dioxide in the atmosphere cause global warming?”, a heat transfer model is suggested.
What about total energy balance considerations, which are an important part of the case for AGW?
You seem to be very dismissive of the total energy balance approach, and attribute it primarily to “meteorologists”. For example, you say:
“ Meteorologists being mainly involved in determining the spatio-temporal changes of some local temperature fields over short periods of time will be eager to disagree with the importance of the LRs as presented in this section. They will point to the fact that in order to evaluate the temperature field one must consider the total energy equation…
But these are meteorological considerations of little relevance to the discussion of what determines an average global surface temperature, and to that avail the various LRs are key notions as reminded to us by Wilde and Mulholland (2020) who state that
“for each atmospheric cell we can compute the average surface temperature if we know the average annual values of the following meteorological parameters:
1. The average height of the tropopause.
2. The average temperature of the tropopause.
3. The average environmental lapse rate of each cell.
Using these three metrics we can then calculate the average surface temperature of each atmospheric circulation cell".
Thus, it is extremely important not to be confused about what is discussed in this section. Notions such as buoyancy, turbulence, diffusion and horizontal motions driven by advection, leading to frontal systems or latent heat released or absorbed, sensible heat, all which are sources and sinks of energy are of course very important, but do not characterize an average global surface temperature, which is as shown before essentially, for a given incoming irradiance level and albedo, the result of the thickness of the atmosphere. One could extrapolate, the thicker the warmer as on Venus, the thinner the colder as on Mars.”
The reference is to
Wilde, S. P. R., and Mulholland, P., 2020. “Return to Earth- A New Mathematical Model of the Earth's Climate”
From which there are statements such as this one:
“The triple-cell parallel adiabatic model of Earth’s climate is tuned to produce the expected value of the average annual atmospheric temperature of 288 Kelvin (15°C) using the previously established method of weighted area to determine the average annual temperature of the Earth.”
These arguments provide no evidence or rationale for why the total energy balance considerations are, as you claim, “irrelevant”. It just seems to have been taken by you that they are irrelevant. A form of “proof by blatant assertion”, perhaps?
Then on page 47 of your ebook:
“One could extrapolate, the thicker the warmer as on Venus, the thinner the colder as on Mars. Let's see how this can be easily asserted. Even though it will be explained further why the usage of Stefan- Boltzmann Law (SBL) is very dubious as planetary bodies are not “black bodies”, a simple calculation using Equation 155 p.91, will be very telling. Starting from the average distances to the Sun of Venus (108.2 106 km), the Earth (150.0 106 km), and Mars (227.9 106 km) and taking the average incoming terrestrial solar flux of 1370 W/m2 as a reference, one can immediately derive values of 2633 W/m2 for Venus and 593 W/m2 for Mars. Using the Bond albedo values of 77% for Venus and 25% for Mars, applying Equation 155 gives:
for Venus: (((1-0.77)*2633)/(4*5.67*10^-8))^(1/4) = 227.32°K=-46.15°C
for the Earth: (((1-0.3)*1370)/(4*5.67*10^-8))^(1/4) = 255.00°K=-18.15°C
for Mars: =(((1-0.25)*593)/(4*5.67*10^-8))^(1/4)=210.44°K = -63.15°C
Thus Venus should be 17 degrees Celsius warmer than Mars by the direct application of SBL, for two atmospheres having comparable composition (≈96% of CO2 for both), using the respective incoming solar fluxes and respective albedo. That's not exactly what is observed, as if the temperature hardly reaches 0°C at the equator on Mars, it stands at 462°C on Venus. Both atmospheres share the same composition with Venus made of 96.5% of CO2 and Mars made of 96% of CO2 and but the remarkable difference is the total masses of their respective atmospheres of 4.8 *10^20 kg for Venus and only 1.5 *10^16 kg for Mars, leading to stark differences of pressure at the ground level of 93 bars on Venus and just a tiny average of 6.36 mbar on Mars. This clearly shows that what explains the difference between the ground temperature of Mars and Venus is certainly not an unproven and dubious radiative greenhouse effect, but simply a massive difference of observed ground pressure. The conclusion is irrefutable, for a given incoming solar flux and a given albedo, it is not the composition but the mass of the atmosphere and thus the ground pressure that determines the average ground temperature.”
(the bold underlining is mine)
On page 48 you summarise your argument thus:
“As a summary, the ground temperature on Earth depends mainly on the atmospheric pressure, insolation (less aerosols and it is the global brightening which replaces the global dimming of the years 1950-1980), air movements (convection / advection) and related transfers of water vapor (evaporation / condensation), ocean motion and currents, and aerosol and nucleation processes having a direct impact on the cloud cover and albedo. The absorption of the thermal infrared radiation by water vapor and carbon dioxide gases only represents a minor effect, and limited to the contribution made by CO2 is just a marginal phenomenon.”
You’ve certainly made some bold claims of irrefutability of ATP and of “unproven and dubious” nature of AGW.
I highly recommend that you compose your materials, and your argument based on them, (which you set out in your pages to 41 to 51) as an academic paper and submit it to credible publications such as Scientific American, New Scientist or Nature.
This is an important step, because you claim your main assertion around atmospheric pressure is “irrefutable” and this needs testing through at least credible peer review, and reviewing for its relevance and applicability to timescales of most interest and concern to onlookers (ie the last couple of hundred years and the next couple of hundred years) .
I hope you will agree that, because of the significance and importance of what you suggest as an alternative theory for explaining global average surface temperatures on Earth, the APT theory should be subjected to at least as much review and checking as AGW has. For example, it should be subject to similar challenges to the ones you have raised in challenging AGW. Is your theory “falsifiable”, in a Popperian sense? Is it testable? How much empirical evidence is there to support it? How much confidence is there in making comparisons between Earth and other planets, and how does that impact on levels of confidence in your conclusions? I assume that it’s much easier to obtain observational and other data about Earth than about other planets, and in much broader and finer detail. How does this impact comparisons between, for example, the confidence and error/uncertainty ranges of scientific work on the greenhouse effect versus work supporting APT that relies on comparisons between planets? What are the uncertainty or error ranges in the data used in the calculations, and in the calculation methods used, for each of these two theories when compared? Is it valid to dismiss the total energy balance considerations, in the way that you have? What is the significance of placing so much focus, in the APT theory, on global average surface temperatures, and very little on changes in climate and the causal relationships between the two? How well does APT theory explain observed and reconstructed temperature changes on Earth, over various timescales, but especially since the industrial revolution (eg using hindcasting)? How good are APT’s predictive abilities? How does work on APT compare with work on the total energy balance of the Earth system, which might have more to say about climate changes, which, after all, occur largely via what happens in the atmosphere rather than on the surface, even though average global surface temperature is a useful way to measure the changes happening to the Earth’s climate?
Note the findings about AGW and its explanatory abilities here:
referencing work that concludes:
“…that natural forcings cannot account for the increase in global temperatures in the second half of the 20th century, and that models using both natural and anthropogenic forcings model the temperature change over the 20th century most accurately.”
And skepticalscience.com adds:
“A number of studies using a variety of different statistical and physical approaches have, like Meehl 2004, estimated the human and natural contributions to global warming. They universally find that humans are the dominant cause of the observed global warming over the past 150 years, 100 years, 50 years, 25 years, etc. In fact, many conclude that natural effects have actually been in the cooling direction in recent decades.”
On page 10 of your ebook, you set out some matters which are part of the consideration of whether or not CO2 has a significant effect on climate:
“So many parameters have an influence on the Earth’s climate and certainly not being exhaustive, one could mention the cyclical variation of the Earth's orbit (i.e. axis inclination, precession7, variations of orbital eccentricity), solar cycles and activity, cloud cover and nucleation processes, oceanic oscillations of all sorts, land usage and over longer periods cataclysmic volcanic activity like Deccan traps (eventually on carbonated substrate), clathrate release mechanisms, distribution and drift of continental masses, even the crossing of galactic dust clouds or arms, etc. and I am omitting many, all combining on different timescales, that one can legitimately wonder whether an additional 100 ppm of CO2 (i.e. 0.01% of the overall atmospheric composition) - generating a supposed +1,6W/m2 overall anthropogenic imbalance (if it really does, in case negative feedbacks have not been underestimated, e.g. Iris effect) - is the driving force of the Earth’s climate ?”
To what extent does the APT theory you suggest tackle and take into account all the factors you mention in the paragraph above, before arriving at a conclusion that CO2 has a minimal effect and, that, instead, atmospheric pressure, rather than composition, is the main determinant of global average surface temperature?
You also suggest, on page 67 of your ebook, that:
“The atmosphere’s moisture content during 61 years from 1948 to 2008, in global average, decreased by about 1%. This amount was the climate process’s automatic dynamic response and was enough to counter the impact of any CO2 and methane increase. Furthermore, the Earth climate system has several other ways to self-regulate the impact of CO2 other than humidity decrease. The possibilities involve modifications in the vertical distribution of water vapor, meridional (latitudinal) distribution of water vapor, meridional distribution of temperature, cloud reaction (e.g. average cloud cover, cloud height, cloud type, cloud thickness, etc.) making it such that “the total long-wave feedback, including cirrus cloud variations, may even be negative” (Lindzen, 2019).”
As an aside, at this point, when you talk about the Earth climate system having “several other ways to self-regulate the impact of CO2” it almost sounds like you’re invoking “Gaia Theory”. But let’s not get into that and continue looking at the science. How do all those “ways to self-regulate the impact of CO2” relate to the main alternative APT theory you suggest explains surface temperature? APT, as described in your ebook, doesn’t seem to include considering them or incorporating them?
I’ve raised just a few questions, unanswered in your ebook, that have occurred to me, who is essentially just an interested lay person. I’m sure people much more expert in the subjects of Earth science, environmental science, climatology, physics and geology could come up with many more questions which could test your theory much more robustly than I could on my own.
This is the nature of the scientific process, I hope you’ll agree. You should expect (and, in fact, demand) no less scrutiny of your ideas than has been brought to bear on, eg, the greenhouse effect in the studies of AGW and climate change.
It seems, on the face of it, that you have expressed an “Atmospheric Pressure Theory” that has a long way to go before it can hope to replace AGW as a means of (better) explaining temperature and climate changes on Earth in modern times and predicting what changes are likely to occur in the near future.
As an aside, there is an interesting discussion of the question “what would happen if all the CO2 in Earth’s atmosphere was removed?” here:
That discussion is somewhat pertinent to discussions about ECS and predictions about future warming.
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