It is often said we must rely on projections from computer simulations of earth’s climate since we have no other earth on which to experiment. That is not actually true since we have observations upon a number of planetary objects in our solar system that also have atmospheres.
This is brought home by a paper, published recently in the journal “Environment Pollution and Climate Change,” written by Ned Nikolov, a Ph.D. in physical science, and Karl Zeller, retired Ph.D. research meteorologist. (title is link to paper). H/T to Tallbloke for posting on this (here) along with comments by one of the authors.
Nikolov and Zeller have written before on this topic, but this paper takes advantage of data from recent decades of space exploration as well as improved observatories. It is thorough, educational and makes a convincing case that a planet’s surface temperatures can be predicted from two variables: distance from the sun, and the atmospheric mass. This post provides some excerpts and exhibits as a synopsis, hopefully to encourage reading the paper itself.
Abstract
A recent study has revealed that the Earth’s natural atmospheric greenhouse effect is around 90 K or about 2.7 times stronger than assumed for the past 40 years. A thermal enhancement of such a magnitude cannot be explained with the observed amount of outgoing infrared long-wave radiation absorbed by the atmosphere (i.e. ≈ 158 W m-2), thus requiring a re-examination of the underlying Greenhouse theory.
We present here a new investigation into the physical nature of the atmospheric thermal effect using a novel empirical approach toward predicting the Global Mean Annual near-surface equilibrium Temperature (GMAT) of rocky planets with diverse atmospheres. Our method utilizes Dimensional Analysis (DA) applied to a vetted set of observed data from six celestial bodies representing a broad range of physical environments in our Solar System, i.e. Venus, Earth, the Moon, Mars, Titan (a moon of Saturn), and Triton (a moon of Neptune).
Twelve relationships (models) suggested by DA are explored via non-linear regression analyses that involve dimensionless products comprised of solar irradiance, greenhouse-gas partial pressure/density and total atmospheric pressure/density as forcing variables, and two temperature ratios as dependent variables. One non-linear regression model is found to statistically outperform the rest by a wide margin.
Above: Venusian Atmosphere
Our analysis revealed that GMATs of rocky planets with tangible atmospheres and a negligible geothermal surface heating can accurately be predicted over a broad range of conditions using only two forcing variables: top-of-the-atmosphere solar irradiance and total surface atmospheric pressure. The hereto discovered interplanetary pressure-temperature relationship is shown to be statistically robust while describing a smooth physical continuum without climatic tipping points.
This continuum fully explains the recently discovered 90 K thermal effect of Earth’s atmosphere. The new model displays characteristics of an emergent macro-level thermodynamic relationship heretofore unbeknown to science that has important theoretical implications. A key entailment from the model is that the atmospheric ‘greenhouse effect’ currently viewed as a radiative phenomenon is in fact an adiabatic (pressure-induced) thermal enhancement analogous to compression heating and independent of atmospheric composition. (my bold)
Earth Atmosphere Density and Temperature Profile
Consequently, the global down-welling long-wave flux presently assumed to drive Earth’s surface warming appears to be a product of the air temperature set by solar heating and atmospheric pressure. In other words, the so-called ‘greenhouse back radiation’ is globally a result of the atmospheric thermal effect rather than a cause for it. (my bold)
Our empirical model has also fundamental implications for the role of oceans, water vapour, and planetary albedo in global climate. Since produced by a rigorous attempt to describe planetary temperatures in the context of a cosmic continuum using an objective analysis of vetted observations from across the Solar System, these findings call for a paradigm shift in our understanding of the atmospheric ‘greenhouse effect’ as a fundamental property of climate.
The research effort demonstrates sound scientific research: data and sources are fully explained, the pattern analysis is replicable, and the conclusions set forth in a logical manner. Alternative hypotheses were explored and rejected in favor of one explaining observations to near perfection, and also showing applicability to other cases.
Equation (10a) implies that GMATs of rocky planets can be calculated as a product of two quantities: the planet’s average surface temperature in the absence of an atmosphere (Tna, K) and a nondimensional factor (Ea ≥ 1.0) quantifying the relative thermal effect of the atmosphere.
As an example of technical descriptions, consider how the paper describes issues relating to the calculation of Tna.
For bodies with tangible atmospheres (such as Venus, Earth, Mars, Titan and Triton), one must calculate Tna using αe=0.132 and ηe=0.00971, which assumes a Moon-like airless reference surface in accordance with our pre-analysis premise. For bodies with tenuous atmospheres (such as Mercury, the Moon, Calisto and Europa), Tna should be calculated from Eq. (4a) (or Eq. 4b respectively if S>0.15 W m-2 and/or Rg ≈ 0 W m-2) using the body’s observed values of Bond albedo αe and ground heat storage fraction ηe.
In the context of this model, a tangible atmosphere is defined as one that has significantly modified the optical and thermo-physical properties of a planet’s surface compared to an airless environment and/or noticeably impacted the overall planetary albedo by enabling the formation of clouds and haze. A tenuous atmosphere, on the other hand, is one that has not had a measurable influence on the surface albedo and regolith thermos-physical properties and is completely transparent to shortwave radiation.
The need for such delineation of atmospheric masses when calculating Tna arises from the fact that Eq. (10a) accurately describes RATEs of planetary bodies with tangible atmospheres over a wide range of conditions without explicitly accounting for the observed large differences in albedos (i.e., from 0.235 to 0.90) while assuming constant values of αe and ηe for the airless equivalent of these bodies. One possible explanation for this counterintuitive empirical result is that atmospheric pressure alters the planetary albedo and heat storage properties of the surface in a way that transforms these parameters from independent controllers of the global temperature in airless bodies to intrinsic byproducts of the climate system itself in worlds with appreciable atmospheres. In other words, once atmospheric pressure rises above a certain level, the effects of albedo and ground heat storage on GMAT become implicitly accounted for by Eq. (11). (my bold)
Significance
Equation (10b) describes the long-term (30 years) equilibrium GMATs of planetary bodies and does not predict inter-annual global temperature variations caused by intrinsic fluctuations of cloud albedo and/or ocean heat uptake. Thus, the observed 0.82 K rise of Earth’s global temperature since 1880 is not captured by our model, since this warming was likely not the result of an increased atmospheric pressure. Recent analyses of observed dimming and brightening periods worldwide [97-99] suggest that the warming over the past 130 years might have been caused by a decrease in global cloud cover and a subsequent increased absorption of solar radiation by the surface. Similarly, the mega shift of Earth’s climate from a ‘hothouse’ to an ‘icehouse’ evident in the sedimentary archives over the past 51 My cannot be explained by Eq. (10b) unless caused by a large loss of atmospheric mass and a corresponding significant drop in surface air pressure since the early Eocene.
Role of greenhouse gases from the new model perspective
Our analysis revealed a poor relationship between GMAT and the amount of greenhouse gases in planetary atmospheres across a broad range of environments in the Solar System (Figures 1-3 and Table 5). This is a surprising result from the standpoint of the current Greenhouse theory, which assumes that an atmosphere warms the surface of a planet (or moon) via trapping of radiant heat by certain gases controlling the atmospheric infrared optical depth [4,9,10]. The atmospheric opacity to LW radiation depends on air density and gas absorptivity, which in turn are functions of total pressure, temperature, and greenhouse-gas concentrations [9]. Pressure also controls the broadening of infrared absorption lines in individual gases. Therefore, the higher the pressure, the larger the infrared optical depth of an atmosphere, and the stronger the expected greenhouse effect would be. According to the present climate theory, pressure only indirectly affects global surface temperature through the atmospheric infrared opacity and its presumed constraint on the planet’s LW emission to Space [9,107].
The artificial decoupling between radiative and convective heat-transfer processes adopted in climate models leads to mathematically and physically incorrect solutions with regard to surface temperature. The LW radiative transfer in a real climate system is intimately intertwined with turbulent convection/advection as both transport mechanisms occur simultaneously. Since convection (and especially the moist one) is orders of magnitude more efficient in transferring energy than LW radiation [3,4], and because heat preferentially travels along the path of least resistance, a properly coupled radiative-convective algorithm of energy exchange will produce quantitatively and qualitatively different temperature solutions in response to a changing atmospheric composition than the ones obtained by current climate models. Specifically, a correctly coupled convective-radiative system will render the surface temperature insensitive to variations in the atmospheric infrared optical depth, a result indirectly supported by our analysis as well. This topic requires further investigation beyond the scope of the present study. (my bold)
The direct effect of atmospheric pressure on the global surface temperature has received virtually no attention in climate science thus far. However, the results from our empirical data analysis suggest that it deserves a serious consideration in the future.
How did Saturn’s moon Titan secure an atmosphere when no other moons in the solar system did? The answer lies largely in its size and location. Here, Titan as imaged in May 2005 by the Cassini spacecraft from about 900,000 miles away. Photo credit: Courtesy NASA/JPL/Space Science Institute
Physical nature of the atmospheric ‘greenhouse effect’
According to Eq. (10b), the heating mechanism of planetary atmospheres is analogous to a gravity-controlled adiabatic compression acting upon the entire surface. This means that the atmosphere does not function as an insulator reducing the rate of planet’s infrared cooling to space as presently assumed [9,10], but instead adiabatically boosts the kinetic energy of the lower troposphere beyond the level of solar input through gas compression. Hence, the physical nature of the atmospheric ‘greenhouse effect’ is a pressure-induced thermal enhancement independent of atmospheric composition. (my bold)
This mechanism is fundamentally different from the hypothesized ‘trapping’ of LW radiation by atmospheric trace gases first proposed in the 19th century and presently forming the core of the Greenhouse climate theory. However, a radiant-heat trapping by freely convective gases has never been demonstrated experimentally. We should point out that the hereto deduced adiabatic (pressure-controlled) nature of the atmospheric thermal effect rests on an objective analysis of vetted planetary observations from across the Solar System and is backed by proven thermodynamic principles, while the ‘trapping’ of LW radiation by an unconstrained atmosphere surmised by Fourier, Tyndall and Arrhenius in the 1800s was based on a theoretical conjecture. The latter has later been coded into algorithms that describe the surface temperature as a function of atmospheric infrared optical depth (instead of pressure) by artificially decoupling radiative transfer from convective heat exchange. Note also that the Ideal Gas Law (PV=nRT) forming the basis of atmospheric physics is indifferent to the gas chemical composition. (my bold)
Climate stability
Our semi-empirical model (Equations 4a, 10b and 11) suggests that, as long as the mean annual TOA solar flux and the total atmospheric mass of a planet are stationary, the equilibrium GMAT will remain stable. Inter-annual and decadal variations of global temperature forced by fluctuations of cloud cover, for example, are expected to be small compared to the magnitude of the background atmospheric warming because of strong negative feedbacks limiting the albedo changes. This implies a relatively stable climate for a planet such as Earth absent significant shifts in the total atmospheric mass and the planet’s orbital distance to the Sun. Hence, planetary climates appear to be free of tipping points, i.e., functional states fostering rapid and irreversible changes in the global temperature as a result of hypothesized positive feedbacks thought to operate within the system. In other words, our results suggest that the Earth’s climate is well buffered against sudden changes.
The hypothesis that a freely convective atmosphere could retain (trap) radiant heat due its opacity has remained undisputed since its introduction in the early 1800s even though it was based on a theoretical conjecture that has never been proven experimentally. It is important to note in this regard that the well-documented enhanced absorption of thermal radiation by certain gases does not imply an ability of such gases to trap heat in an open atmospheric environment. This is because, in gaseous systems, heat is primarily transferred (dissipated) by convection (i.e., through fluid motion) rather than radiative exchange. (my bold)
If gases of high LW absorptivity/emissivity such as CO2, methane and water vapor were indeed capable of trapping radiant heat, they could be used as insulators. However, practical experience has taught us that thermal radiation losses can only be reduced by using materials of very low IR absorptivity/emissivity and correspondingly high thermal reflectivity such as aluminum foil. These materials are known among engineers at NASA and in the construction industry as radiant barriers [129]. It is also known that high-emissivity materials promote radiative cooling. Yet, all climate models proposed since 1800s were built on the premise that the atmosphere warms Earth by limiting radiant heat losses of the surface through to the action of IR absorbing gases aloft.
If a trapping of radiant heat occurred in Earth’s atmosphere, the same mechanism should also be expected to operate in the atmospheres of other planetary bodies. Thus, the Greenhouse concept should be able to mathematically describe the observed variation of average planetary surface temperatures across the Solar System as a continuous function of the atmospheric infrared optical depth and solar insolation. However, to our knowledge, such a continuous description (model) does not exist.
Summary
The planetary temperature model consisting of Equations (4a), (10b), (11) has several fundamental theoretical implications, i.e.,
• The ‘greenhouse effect’ is not a radiative phenomenon driven by the atmospheric infrared optical depth as presently believed, but a pressure-induced thermal enhancement analogous to adiabatic heating and independent of atmospheric composition;
• The down-welling LW radiation is not a global driver of surface warming as hypothesized for over 100 years but a product of the near-surface air temperature controlled by solar heating and atmospheric pressure;
• The albedo of planetary bodies with tangible atmospheres is not an independent driver of climate but an intrinsic property (a byproduct) of the climate system itself. This does not mean that the cloud albedo cannot be influenced by external forcing such as solar wind or galactic cosmic rays. However, the magnitude of such influences is expected to be small due to the stabilizing effect of negative feedbacks operating within the system. This novel understanding explains the observed remarkable stability of planetary albedos;
• The equilibrium surface temperature of a planet is bound to remain stable (i.e., within ± 1 K) as long as the atmospheric mass and the TOA mean solar irradiance are stationary. Hence, Earth’s climate system is well buffered against sudden changes and has no tipping points;
• The proposed net positive feedback between surface temperature and the atmospheric infrared opacity controlled by water vapor appears to be a model artifact resulting from a mathematical decoupling of the radiative-convective heat transfer rather than a physical reality.
Update July 13, 2017
Michael Lewis pointed to a link on this subject in his comment below. Reading again the discussion thread, I appreciated again this point by point response from Kristian to Tim Folkerts so I am adding it to the post. (To be clear, T_e means emission temperature (same as Tna in the article above, while T_s means surface temperature.)
Kristian says:
August 4, 2016 at 9:24 AM
Tim Folkerts says, August 3, 2016 at 3:33 PM:
“In any case, it seems we both agree that the atmosphere has some warming effect.”
That’s quite obvious. You only need to compare Earth’s T_s with the Moon’s.
“I agree that the mass itself plays a role. Mass creates thermal inertia to even out temperature swings. The mass of the atmosphere (and oceans) also allows convection to carry energy from warmer areas to cooler areas, which further reduces variations. By themselves, these could do no more than bring T_s UP TOWARD T_e.”
True.
“I see no physics that would explain mass itself raising T_s ABOVE T_e.”
Just as the radiative properties of gaseous molecules are also not able – all by themselves – to raise a planet’s T_s above its T_e. No, both mass and radiative properties are needed.
“To get above T_e we need something to change the outgoing thermal radiation, eg GHGs at a high enough altitude to be significantly cooler than the surface.”
Yes, but then we also need an air column above the solar-heated surface that can have such a “high enough altitude” in the first place. We also need that altitude to be cooler on average than the surface. IOW, we need mass. A certain gas density/pressure (molecular interaction). And we need fluid dynamics.
“So the key factor is ALTITUDE here (with some definite dependence of the concentrations of the GHGs as well).”
No. There is no dependence on the CONCENTRATION/CONTENT of IR-active constituents in an atmosphere. An atmosphere definitely needs to be IR active (although it’s evidently not enough) for a planet’s T_s to become higher than its T_e. It also needs to be IR active to be able to adequately rid itself of its absorbed energy from the surface (radiatively AND non-radiatively transferred) and directly from the Sun. But once it’s IR active, there is no dependence on the degree of activity. Because then the atmosphere has become stably convectively operative. And all that matters from then on is atmospheric MASS and SOLAR INPUT (TSI and global albedo).
“You say that atmospheric mass seems to force. Do you think that mass alone without GHGs could force temperatures higher than T_e?”
No. Just like “GHGs” alone could also not force T_s higher than T_e. You need both.
* * *
So I say: There IS a “GHE”. But it’s ultimately massively caused. The radiative properties are simply a tool. A means to an end. And there definitely ISN’T an “anthropogenically enhanced GHE” (AGW). It cannot happen.
Science Matters 
Thanks for putting this up, Ron. I’ve been working with this for the last couple of days. If it’s replicable, it’s a game changer!
It will be attacked as insufficient consideration of the role of greenhouse gases, of course, Nevertheless, the bulk of the analysis of a universal process of atmospheric dynamics is undeniable and easily tested.
I expect to see pulled hair and gnashed teeth throughout the blogosphere!
LikeLiked by 1 person
Thanks for the comment Michael. This is a paper I was waiting for to put the math comparing earth to other planets with atmospheres. This finding is consistent with other descriptions, such as Salby and the research on lapse rate data from balloons done by the Connellys. More evidence that the radiative effect is highly exaggerated in the real world.
LikeLike
Reblogged this on Climate Collections.
LikeLike
Here is Roy Spencer’s take on the atmospheric pressure model, posted a year ago. It sounds like he was not addressing exactly what is proposed in this article.
LikeLike
http://www.drroyspencer.com/2016/07/the-warm-earth-greenhouse-effect-or-atmospheric-pressure/
LikeLike
Thanks for that link Michael. I remember reading through that thread, and will look at it again. Spencer is a hero for what he does, but does have a blind spot here, I believe. Some skeptics are so concerned not to be labeled a “denier”. and cast into the outer darkness that they do not question this fundamental issue. One of Spencer’s points was that the pressure determination of warming does not specify the absolute temperature to be found at the surface (really 2 meters above the surface). Nikolov and Zeller deal with that in spades.
LikeLike
That was my impression, too. “Avert the eyes!”
LikeLike
Michael, IMO the best part of that thread was a point by point response from Kristian to Tim Folkerts. I am adding it above to the post. To be clear, T_e means emission temperature (same as Tna in the article above, while T_s means surface temperature
Kristian says:
August 4, 2016 at 9:24 AM
Tim Folkerts says, August 3, 2016 at 3:33 PM:
“In any case, it seems we both agree that the atmosphere has some warming effect.”
That’s quite obvious. You only need to compare Earth’s T_s with the Moon’s.
“I agree that the mass itself plays a role. Mass creates thermal inertia to even out temperature swings. The mass of the atmosphere (and oceans) also allows convection to carry energy from warmer areas to cooler areas, which further reduces variations. By themselves, these could do no more than bring T_s UP TOWARD T_e.”
True.
“I see no physics that would explain mass itself raising T_s ABOVE T_e.”
Just as the radiative properties of gaseous molecules are also not able – all by themselves – to raise a planet’s T_s above its T_e. No, both mass and radiative properties are needed.
“To get above T_e we need something to change the outgoing thermal radiation, eg GHGs at a high enough altitude to be significantly cooler than the surface.”
Yes, but then we also need an air column above the solar-heated surface that can have such a “high enough altitude” in the first place. We also need that altitude to be cooler on average than the surface. IOW, we need mass. A certain gas density/pressure (molecular interaction). And we need fluid dynamics.
“So the key factor is ALTITUDE here (with some definite dependence of the concentrations of the GHGs as well).”
No. There is no dependence on the CONCENTRATION/CONTENT of IR-active constituents in an atmosphere. An atmosphere definitely needs to be IR active (although it’s evidently not enough) for a planet’s T_s to become higher than its T_e. It also needs to be IR active to be able to adequately rid itself of its absorbed energy from the surface (radiatively AND non-radiatively transferred) and directly from the Sun. But once it’s IR active, there is no dependence on the degree of activity. Because then the atmosphere has become stably convectively operative. And all that matters from then on is atmospheric MASS and SOLAR INPUT (TSI and global albedo).
“You say that atmospheric mass seems to force. Do you think that mass alone without GHGs could force temperatures higher than T_e?”
No. Just like “GHGs” alone could also not force T_s higher than T_e. You need both.
* * *
So I say: There IS a “GHE”. But it’s ultimately massively caused. The radiative properties are simply a tool. A means to an end. And there definitely ISN’T an “anthropogenically enhanced GHE” (AGW). It cannot happen.
LikeLike
Thanks for sharing this very interesting article, Ron.
I’d like to highlight the following comment from their article,
“… Recent analyses of observed dimming and brightening periods worldwide [97-99] suggest that the warming over the past 130 years might have been caused by a decrease in global cloud cover and a subsequent increased absorption of solar radiation by the surface. Similarly, the mega shift of Earth’s climate from a ‘hothouse’ to an ‘icehouse’ evident in the sedimentary archives over the past 51 My cannot be explained by Eq. (10b) unless caused by a large loss of atmospheric mass and a corresponding significant drop in surface air pressure since the early Eocene…”
Their model seems to be “too centered” on thermodynamic properties of atmospheres and, perhaps, not very attentive to solar variation.
It would be interesting to see how it compares with short period variation – specially the strong ones – like the periods of strong ENSO or very low solar activity like in 2008-09,
LikeLike
LikeLike
Thanks dmh, I also want to follow up on their comment regarding brightening and dimming effects on GMAT. Since the paper is addressing equilibrium GMAT as determined by insolation and thermal effect of atmospheres, they point out that fluctuations around equilibrium are not explained by this framework. Millennial changes are likely orbital in nature, and the multidecadal ones are the issue. Oceanic oscillations force ups and downs that offset over about 60 years, but people can and do misread a short temperature rise like that from 1976 to 1998. What caused the Little Ice Age, and what ended it is the missing piece.
LikeLiked by 1 person
Dmh, I did a follow up post on the dimming/brightening issue called Nature’s Sunscreen:
https://rclutz.wordpress.com/2017/07/17/natures-sunscreen/
LikeLike
Hmmmm…. I would look forward to seeing how this stands up. It is only 320 am my time and I am a bit sleepy. But my question would be along the lines of can you please show a corrected energy budget that puts irradiance in its proper contribution and shows convection in its actual role? This seems perilously close to that Cotton kook….
That said, I have often thought about why good ol’ PV = nrT and its implications stabilizing temps is sort of skipped over…
LikeLike
Thanks for stopping by and commenting hunter. You have your finger on the key point IMO. The supposition that radiation can determine air temperatures apart from convection, when as the paper points out, heat flows take the path of least resistance among options available. That means in a planetary climate, convection rules near the surface, and radiation does its thing higher up and near the top. I am adding an update on this point to the post above.
As for the energy balance, I am partial to this one from ERBE:
More at https://rclutz.wordpress.com/2017/05/17/the-curious-case-of-dr-miskolczi/
LikeLiked by 1 person
Gravity obviously has a role in temperature production, hence water stops getting colder at some depth in the sea as the pressure increases (does it?).
Similarly the atmosphere cools high up even though closer to the sun.
I do not think this rules out the observation on CO2 effect in an atmosphere.
At whatever pressure you postulate the GHH properties will have an effect on the temperature.
Climate sensitivity is more likely determined by the other changes in albedo that are temperature sensitive like clouds and colour.
LikeLiked by 1 person
Many people think CO2 affects the atmospheric temperature profile, and climate models presume it, but effects from CO2 have yet to be detected in observations. For example, weather balloon records should show it, but they do not.
“Atmospheric profiles in North America during the period 2010-2011, obtained from archived radiosonde measurements, were analysed in terms of changes in molar density (D) with pressure (P). This revealed a pronounced phase change at the tropopause. The air above the tropopause (i.e., in the tropopause/stratosphere) adopted a “heavy phase”, distinct from the conventional “light phase” found in the troposphere. This heavy phase was also found in the lower troposphere for cold, Arctic winter radiosondes.”
“Reasonable fits for the complete barometric temperature profiles of all the considered radiosondes could be obtained by just accounting for these phase changes and for changes in humidity. This suggests that the well-known changes in temperature lapse rates associated with the tropopause/stratosphere regions are related to the phase change, and not “ozone heating”, which had been the previous explanation.”
“Possible correlations between solar ultraviolet variability and climate change have previously been explained in terms of changes in ozone heating influencing stratospheric weather. These explanations may have to be revisited, but the correlations may still be valid, e.g., if it transpires that solar variability influences the formation of the heavy phase, or if the changes in incoming ultraviolet radiation are redistributed throughout the atmosphere, after absorption in the stratosphere.”
“The fits for the barometric temperature profiles did not require any consideration of the composition of atmospheric trace gases, such as carbon dioxide, oxone or methane. This contradicts the predictions of current atmospheric models, which assume the temperature profiles are strongly influenced by greenhouse gas concentrations. This suggests that the greenhouse effect plays a much smaller role in barometric temperature profiles than previously assumed.”
http://oprj.net/articles/atmospheric-science/19
The theory is looking more and more like a celestial teapot.
https://rclutz.wordpress.com/2017/01/20/the-climate-change-teapot/
LikeLiked by 1 person
What caused the warming in the past couple of decades if it was not carbon dioxide? The sun’s output was in decline over that time period. I am unclear as to what causes the atmospheric compression which the authors of the study seem to be saying causes the warming.
LikeLike
Russ, the authors discuss what sets the baseline surface temperature, from which there are small warming and cooling fluctuations unrelated to atmospheric mass and distance from the sun. From the paper:
“Our semi-empirical model (Equations 4a, 10b and 11) suggests that, as long as the mean annual TOA solar flux and the total atmospheric mass of a planet are stationary, the equilibrium GMAT will remain stable. Inter-annual and decadal variations of global temperature forced by fluctuations of cloud cover, for example, are expected to be small compared to the magnitude of the background atmospheric warming because of strong negative feedbacks limiting the albedo changes. This implies a relatively stable climate for a planet such as Earth absent significant shifts in the total atmospheric mass and the planet’s orbital distance to the Sun.”
There are other more powerful factors than CO2 causing cooling as in the 1950s and 60s, and warming in the 80s and 90s. For example, studies of cloudiness show a dimming (reduced sunshine at the surface) during the cooling period and brightening (more sunshine) heating the oceans during the 80s and 90s. See post: https://rclutz.wordpress.com/2017/07/17/natures-sunscreen/
This century there is clear evidence of the oceans releasing heat as I have shown in the post:
https://rclutz.wordpress.com/2017/12/11/oceans-cool-post-nino/
LikeLike
Thanks for your explanation Ron. Perhaps the cosmic ray influence on cloud formation plays an important role too and undersea volcanoes. It’s a big complex universe. I have been following the adapt 2030 videos on youtube and some others that do show some good evidence that the climate is cooling now and the arctic sea ice is growing.
LikeLike
I’m sorry, but Nikolov and Zeller’s claims are nonsense. All they have done is curve fitting. See the two posts below for a thorough fisking of their nonsense.
w.
https://wattsupwiththat.com/2012/01/23/the-mystery-of-equation-8/
http://wattsupwiththat.com/2012/01/13/a-matter-of-some-gravity/
LikeLike
Willis, it seems you are stuck in 2012. Nikolov and Zeller responded and dismissed your claims back then.
https://tallbloke.wordpress.com/2012/02/09/nikolov-zeller-reply-eschenbach/
This is a different discussion:
“We present here a new investigation into the physical nature of the atmospheric thermal effect using a novel empirical approach toward predicting the Global Mean Annual near-surface equilibrium Temperature (GMAT) of rocky planets with diverse atmospheres. Our method utilizes Dimensional Analysis (DA) applied to a vetted set of observed data from six celestial bodies representing a broad range of physical environments in our Solar System, i.e. Venus, Earth, the Moon, Mars, Titan (a moon of Saturn), and Triton (a moon of Neptune).”
It is thorough, educational and makes a convincing case that a planet’s surface temperatures can be predicted from two variables: distance from the sun, and the atmospheric mass.
LikeLike
Ron, N&Z claim that on a planet with a dense transparent atmosphere with no greenhouse gases the surface temperature will be elevated above the Stefan-Boltzmann temperature. This means that the surface will be emitting more energy than it is receiving, which violates the laws of conservation of energy.
N&Z did NOT answer that objection in their 2012 screed. Nor did they discuss the ease with which one can fit a mere eight data points with five tunable parameters and free choice of equations.
In that regard, they only discussed the less accurate of my two proposed replacements for their curve-fitting exercise. The more accurate of my two proposed replacements has three-quarters of the RMS error of theirs … but they didn’t have the balls to even mention that.
So no, they did not “dismiss” my claims.
Next, they flat-out lied about the temperature of Mars by carefully picking a bogus value (180K) because it fit their magic equation to within 0.1°C … instead of using the generally accepted value (210K) which gives a 30°C error.
Next, although they used the earth’s moon as one of their data points, they didn’t use either of Mar’s moons, nor the dwarf planet Ceres. Why not?
Well, because their magic equation doesn’t fit them in the slightest. It is way, way wrong for those planetary bodies, so they just ignored them.
Sorry, Ron, but you’ve been sold a bill of goods by a pair of master manipulators. Please read the two links I sent. If you can find anything wrong with them, please let me know … because N&Z certainly could find nothing wrong with them.
Best of the New Year to you and yours,
w.
LikeLike
I am persuaded that Kristian has it right above:
“There is no dependence on the CONCENTRATION/CONTENT of IR-active constituents in an atmosphere. An atmosphere definitely needs to be IR active (although it’s evidently not enough) for a planet’s T_s to become higher than its T_e. It also needs to be IR active to be able to adequately rid itself of its absorbed energy from the surface (radiatively AND non-radiatively transferred) and directly from the Sun. But once it’s IR active, there is no dependence on the degree of activity. Because then the atmosphere has become stably convectively operative. And all that matters from then on is atmospheric MASS and SOLAR INPUT (TSI and global albedo).”
LikeLike
Ron, Kristian says that, but that is definitely NOT what N&Z say. Show me where in their equation there is anything about GHGs … doesn’t exist. Therefore, their system must perforce work WITHOUT any GHGs.
Regards,
w.
LikeLike
Willis, I agree that N&Z are focusing on the role of solar and atmospheric mass because it has been ignored in climate analysis by both warmists and skeptics. The role of radiative gases, dominated by H2O, is critical to the cooling of the planet at TOA, and also facilitates the convective overturning within the troposphere.
AFAIK they never argued that solar irradiance & atmospheric pressure solely determine the global temperature at all time scales. Absolutely not! These drivers only set up the bulk of the global average temperature, i.e. the main “energy envelope” so to speak, around which small fluctuation (in the order of ±1.0 C) are possible and do occur. These fluctuations are driven by changes in cloud cover/albedo and short-lived aerosol emissions from volcanic eruptions. Cloud cover changes impact global temperature on time scales from years to centuries, while effects of volcanic eruptions typically last 2-3 years (not even a climatological time period)…
There are a number of processes operating to produce earth’s climate. I think N&Z provide an interesting framework within which other processes function, such as brightening/dimming and hydrology cycling.
LikeLike
Ron Clutz
Ron, there is not any reference to GHGs in their magical formula. None. Their claim is that atmospheric processes cause the ~ 33°C extra warmth of Earth’s atmosphere.
Perhaps you could explain what the energy SOURCE is for that additional warmth. After albedo losses, about 240 W/m2 enters the climate system. That would give us a theoretical temperature of ~255K. We are currently at about 288K. N&Z claim this is from some atmospheric process.
Now, at 288K the surface radiates about 390W/m2 … so my question to you is, what is the SOURCE of that additional constant 150 W/m2? That is a LOT of energy. Sunlight striking the surface is only about 169 W/m2, so their mystery source is providing almost as much energy as the sun does … where is that coming from?
I mean, we know that the sun’s energy comes from nuclear fusion. And we get energy from nuclear reactions. We get energy from stored fossil fuels.
But what is the SOURCE of Nikolov’s mystery 150 W/m2?? If you cannot answer that in terms that a schoolkid can understand, then you’re just believing …
Next, did you read my two links? Because if you have and you cannot find any errors in what I wrote, then N&Z are wrong. Not just slightly in error. Totally wrong.
I invite you to point out where the error in my work is … or to identify the source of Nikolov’s mystery 150 W/m2 …
Regards,
w.
LikeLike
Willis, thanks for commenting. I won’t be joining your crusade to prove N&Z wrong. I won’t attempt to reconcile your equations with theirs; too many numbers and assumptions floating, including applying SB to the earth’s surface as though it were a black body, when in fact it is an irregular surface encased in an atmosphere. You seem certain you know the right answer, while I am not there by a long shot. My concern is what N&Z got right, not what is missing in their explanation. They are pointing out something long known but too often ignored when analyzing climate matters.
It seems clear that distance from the sun and atmospheric mass determine the fundamental range of planetary temperatures that are possible. We have only to look at Earth, our Moon, Mars and Venus. Obviously, planet Ocean (misnamed Earth) makes the ambient surface temperature at night much warmer than the dark side of the Moon by storing solar energy during daytime. And water in the atmosphere forms clouds functioning as a sunscreen to limit the daytime heating. As well, the ocean and air circulate to spread the solar energy over the entire planet surface, rather being limited to the sunlit side. End result is the Moon gets the same solar input, but has extreme temperatures for lack of an ocean and atmosphere. That’s why we live here, and not there.
Mars provides a confirmation of what N&Z (and others before them) are saying. Mars has an atmosphere very much like ours, if you take away the O2 and N2, thereby losing the bulk of our atmosphere. Mars has plenty of IR-active gases, even without H2O. Result: Mars is much colder than Earth partly because it is further away from the the sun, but mostly because its low atmospheric mass is not able to retain heat.
From the European Space Agency:
As a complete contrast to Venus, there is Mars. The Red Planet displays hardly any greenhouse effect. Mars does have some atmospheric carbon dioxide, but almost no atmosphere! The existing atmosphere is so thin that it cannot retain energy from the Sun.
Venus of course is at the other end of the spectrum. It is both closer to the sun and also has a massive atmosphere, so dense the surface is not heated directly by the sun, but rather secondarily by the atmosphere. Result: Venus has extremely higher temperatures, a combination of greater insolation and atmospheric mass.
I conclude that each planet’s temperature is constrained by solar input and atmospheric mass, but that the mechanisms causing each climate are particular to unique characteristics of surface and atmospheric composition.
As I said above, I do not have a comprehensive climate theory, nor have I seen one that inspires certainty. Although I have high regard for your work on the hydrology thermostat. There are still missing pieces, and incomplete understanding of interactions of processes. Others surely know more than I, but still we are blind men grasping an elephant.
That’s how I see it, and I won’t be commenting further for now.
LikeLike