Note: This was a poster, and adopted into a blog post by the author, Ned Nikolov, specifically for WUWT. My thanks to him for the extra effort in converting the poster to a more blog friendly format. – Anthony
Expanding the Concept of Atmospheric Greenhouse Effect Using Thermodynamic Principles: Implications for Predicting Future Climate Change
Ned Nikolov, Ph.D. & Karl Zeller, Ph.D.
USFS Rocky Mountain Research Station, Fort Collins CO, USA
Emails: ntconsulting@comcast.net kzeller@colostate.edu
Poster presented at the Open Science Conference of the World Climate Research Program,
24 October 2011, Denver CO, USA
http://www.wcrp-climate.org/conference2011/posters/C7/C7_Nikolov_M15A.pdf
Abstract
We present results from a new critical review of the atmospheric Greenhouse (GH) concept. Three main problems are identified with the current GH theory. It is demonstrated that thermodynamic principles based on the Gas Law need be invoked to fully explain the Natural Greenhouse Effect. We show via a novel analysis of planetary climates in the solar system that the physical nature of the so-called GH effect is a Pressure-induced Thermal Enhancement (PTE), which is independent of the atmospheric chemical composition. This finding leads to a new and very different paradigm of climate controls. Results from our research are combined with those from other studies to propose a new Unified Theory of Climate, which explains a number of phenomena that the current theory fails to explain. Implications of the new paradigm for predicting future climate trends are briefly discussed.
1. Introduction
Recent studies revealed that Global Climate Models (GCMs) have significantly overestimated the Planet’s warming since 1979 failing to predict the observed halt of global temperature rise over the past 13 years. (e.g. McKitrick et al. 2010). No consensus currently exists as to why the warming trend ceased in 1998 despite a continued increase in atmospheric CO2 concentration. Moreover, the CO2-temperature relationship shows large inconsistencies across time scales. In addition, GCM projections heavily depend on positive feedbacks, while satellite observations indicate that the climate system is likely governed by strong negative feedbacks (Lindzen & Choi 2009; Spencer & Braswell 2010). At the same time, there is a mounting political pressure for Cap-and-Trade legislation and a global carbon tax, while scientists and entrepreneurs propose geo-engineering solutions to cool the Planet that involve large-scale physical manipulation of the upper atmosphere. This unsettling situation calls for a thorough reexamination of the present climate-change paradigm; hence the reason for this study.
2. The Greenhouse Effect: Reexamining the Basics
Figure 1. The Atmospheric Greenhouse Effect as taught at universities around the World (diagram from the website of the Penn State University Department of Meteorology).
According to the current theory, the Greenhouse Effect (GHE) is a radiative phenomenon caused by heat-trapping gases in the atmosphere such as CO2 and water vapor that are assumed to reduce the rate of surface infrared cooling to Space by absorbing the outgoing long-wave (LW) emission and re-radiating part of it back, thus increasing the total energy flux toward the surface. This is thought to boost the Earth’s temperature by 18K – 33K compared to a gray body with no absorbent atmosphere such as the Moon; hence making our Planet habitable. Figure 1 illustrates this concept using a simple two-layer system known as the Idealized Greenhouse Model (IGM). In this popular example, S is the top-of-the atmosphere (TOA) solar irradiance (W m-2), A is the Earth shortwave albedo, Ts is the surface temperature (K), Te is the Earth’s effective emission temperature (K) often equated with the mean temperature of middle troposphere, ϵ is emissivity, and σ is the Stefan-Boltzmann (S-B) constant.
2.1. Main Issues with the Current GHE Concept:
A) Magnitude of the Natural Greenhouse Effect. GHE is often quantified as a difference between the actual mean global surface temperature (Ts = 287.6K) and the planet’s average gray-body (no-atmosphere) temperature (Tgb), i.e. GHE = Ts – Tgb. In the current theory, Tgb is equated with the effective emission temperature (Te) calculated straight from the S-B Law using Eq. (1):
where αp is the planetary albedo of Earth (≈0.3). However, this is conceptually incorrect! Due to Hölder’s inequality between non-linear integrals (Kuptsov 2001), Te is not physically compatible with a measurable true mean temperature of an airless planet. To be correct, Tgb must be computed via proper spherical integration of the planetary temperature field. This means calculating the temperature at every point on the Earth sphere first by taking the 4th root from the S-B relationship and then averaging the resulting temperature field across the planet surface, i.e.
where αgb is the Earth’s albedo without atmosphere (≈0.125), μ is the cosine of incident solar angle at any point, and cs= 13.25e-5 is a small constant ensuring that Tgb = 2.72K (the temperature of deep Space) when So = 0. Equation (2) assumes a spatially constant albedo (αgb), which is a reasonable approximation when trying to estimate an average planetary temperature.
Since in accordance with Hölder’s inequality Tgb ≪ Te (Tgb =154.3K ), GHE becomes much larger than presently estimated.
According to Eq. (2), our atmosphere boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K! This raises the question: Can a handful of trace gases which amount to less than 0.5% of atmospheric mass trap enough radiant heat to cause such a huge thermal enhancement at the surface? Thermodynamics tells us that this not possible.
B) Role of Convection. The conceptual model in Fig. 1 can be mathematically described by the following simultaneous Equations (3),
where νa is the atmospheric fraction of the total shortwave radiation absorption. Figure 2 depicts the solution to Eq. (3) for temperatures over a range of atmospheric emissivities (ϵ) assuming So = 1366 W m-2 and νa =0.326 (Trenberth et al. 2009). An increase in atmospheric emissivity does indeed cause a warming at the surface as stated by the current theory. However, Eq. (3) is physically incomplete, because it does not account for convection, which occurs simultaneously with radiative transfer. Adding a convective term to Eq. (3) (such as a sensible heat flux) yields the system:
where gbH is the aerodynamic conductance to turbulent heat exchange. Equation (4) dramatically alters the solution to Eq. (3) by collapsing the difference between Ts, Ta and Te and virtually erasing the GHE (Fig. 3). This is because convective cooling is many orders of magnitude more efficient that radiative cooling. These results do not change when using multi-layer models. In radiative transfer models, Ts increases with ϵ not as a result of heat trapping by greenhouse gases, but due to the lack of convective cooling, thus requiring a larger thermal gradient to export the necessary amount of heat. Modern GCMs do not solve simultaneously radiative transfer and convection. This decoupling of heat transports is the core reason for the projected surface warming by GCMs in response to rising atmospheric greenhouse-gas concentrations. Hence, the predicted CO2-driven global temperature change is a model artifact!
Figure 2. Solution to the two-layer model in Eq. (3) for Ts and Ta as a function of atmospheric emissivity assuming a non-convective atmosphere. Also shown is the predicted down-welling LW flux(Ld). Note that Ld ≤ 239 W m-2.
Figure 3. Solution to the two-layer model in Eq. (4) for Ts and Ta as a function of atmospheric emissivity assuming a convective atmosphere (gbH = 0.075 m/s). Also shown is the predicted down-welling LW flux (Ld). Note that Ld ≤ 239 W m-2.
Figure 4. According to observations, the Earth-Atmosphere System absorbs on average a net solar flux of 239 W m-2, while the lower troposphere alone emits 343 W m-2 thermal radiation toward the surface.
C) Extra Kinetic Energy in the Troposphere.
Observations show that the lower troposphere emits 44% more radiation toward the surface than the total solar flux absorbed by the entire Earth-Atmosphere System (Pavlakis et al. 2003) (Fig. 4). Radiative transfer alone cannot explain this effect (e.g. Figs. 2 & 3) given the negligible heat storage capacity of air, no matter how detailed the model is. Thus, empirical evidence indicates that the lower atmosphere contains more kinetic energy than provided by the Sun. Understanding the origin of this extra energy is a key to the GHE.
3. The Atmospheric Thermal Enhancement
Previous studies have noted that the term Greenhouse Effect is a misnomer when applied to the atmosphere, since real greenhouses retain heat through an entirely different mechanism compared to the free atmosphere, i.e. by physically trapping air mass and restricting convective heat exchange. Hence, we propose a new term instead, Near-surface Atmospheric Thermal Enhancement (ATE) defined as a non-dimensional ratio (NTE) of the planet actual mean surface air temperature (Ts, K) to the average temperature of a Standard Planetary Gray Body (SPGB) with no atmosphere (Tgb, K) receiving the same solar irradiance, i.e. NTE = Ts /Tgb. This new definition emphasizes the essence of GHE, which is the temperature boost at the surface due to the presence of an atmosphere. We employ Eq. (2) to estimate Tgb assuming an albedo αgb = 0.12 and a surface emissivity ϵ = 0.955 for the SPGB based on data for Moon, Mercury, and the Earth surface. Using So = 1362 W m-2 (Kopp & Lean 2011) in Eq. (2) yields Tgb = 154.3K and NTE = 287.6/154.3 = 1.863 for Earth. This prompts the question: What mechanism enables our atmosphere to boost the planet surface temperature some 86% above that of a SPGB? To answer it we turn on to the classical Thermodynamics.
3.1. Climate Implications of the Ideal Gas Law
The average thermodynamic state of a planet’s atmosphere can be accurately described by the Ideal Gas Law (IGL):
PV = nRT (5)
where P is pressure (Pa), V is the gas volume (m3), n is the gas amount (mole), R = 8.314 J K-1 mol-1is the universal gas constant, and T is the gas temperature (K). Equation (5) has three features that are chiefly important to our discussion: a) the product P×V defines the internal kinetic energy of a gas (measured in Jules) that produces its temperature; b) the linear relationship in Eq. (5) guarantees that a mean global temperature can be accurately estimated from planetary averages of surface pressure and air volume (or density). This is in stark contrast to the non-linear relationship between temperature and radiant fluxes (Eq. 1) governed by Hölder’s inequality of integrals; c) on a planetary scale, pressure in the lower troposphere is effectively independent of other variables in Eq. (5) and is only a function of gravity (g), total atmospheric mass (Mat), and the planet surface area (As), i.e. Ps = g Mat/As. Hence, the near-surface atmospheric dynamics can safely be assumed to be governed (over non-geological time scales) by nearly isobaric processes on average, i.e. operating under constant pressure. This isobaric nature of tropospheric thermodynamics implies that the average atmospheric volume varies in a fixed proportion to changes in the mean surface air temperature following the Charles/Gay-Lussac Law, i.e. Ts/V = const. This can be written in terms of the average air density ρ (kg m-3) as
ρTs = const. = Ps M / R (6)
where Ps is the mean surface air pressure (Pa) and M is the molecular mass of air (kg mol-1). Eq. (6) reveals an important characteristic of the average thermodynamic process at the surface, namely that a variation of global pressure due to either increase or decrease of total atmospheric mass will alter both temperature and atmospheric density. What is presently unknown is the differential effect of a global pressure change on each variable. We offer a solution to this in & 3.3. Equations (5) and (6) imply that pressure directly controls the kinetic energy and temperature of the atmosphere. Under equal solar insolation, a higher surface pressure (due to a larger atmospheric mass) would produce a warmer troposphere, while a lower pressure would result in a cooler troposphere. At the limit, a zero pressure (due to the complete absence of an atmosphere) would yield the planet’s gray-body temperature.
The thermal effect of pressure is vividly demonstrated on a cosmic scale by the process of star formation, where gravity-induced rise of gas pressure boosts the temperature of an interstellar cloud to the threshold of nuclear fusion. At a planetary level, the effect is manifest in Chinook winds, where adiabatically heated downslope airflow raises the local temperature by 20C-30C in a matter of hours. This leads to a logical question: Could air pressure be responsible for the observed thermal enhancement at the Earth surface presently known as a ‘Natural Greenhouse Effect’? To answer this we must analyze the relationship between NTEfactor and key atmospheric variables including pressure over a wide range of planetary climates. Fortunately, our solar system offers a suitable spectrum of celestial bodies for such analysis.
3.2. Interplanetary Data Set
We based our selection of celestial bodies for the ATE analysis on three criteria: 1) presence of a solid planetary surface with at least traces of atmosphere; 2) availability of reliable data on surface temperature, total pressure, atmospheric composition etc. preferably from direct measurements; and 3) representation of a wide range of atmospheric masses and compositions. This approach resulted in choosing of four planets – Mercury, Venus, Earth, and Mars, and four natural satellites – Moon of Earth, Europa of Jupiter, Titan of Saturn, and Triton of Neptune. Each celestial body was described by 14 parameters listed in Table 1.
For planets with tangible atmospheres, i.e. Venus, Earth and Mars, the temperatures calculated from IGL agreed rather well with observations. Note that, for extremely low pressures such as on Mercury and Moon, the Gas Law produces Ts ≈ 0.0. The SPGB temperatures for each celestial body were estimated from Eq. (2) using published data on solar irradiance and assuming αgb = 0.12 and ϵ = 0.955. For Mars, global means of surface temperature and air pressure were calculated from remote sensing data retrieved via the method of radio occultation by the Radio Science Team (RST) at Stanford University using observations by the Mars Global Surveyor (MGS) spacecraft from 1999 to 2005. Since the MGS RST analysis has a wide spatial coverage, the new means represent current average conditions on the Red Planet much more accurately than older data based on Viking’s spot observations from 1970s.
Table 1. Planetary data used to analyze the physical nature of the Atmospheric Near-Surface Thermal Enhancement (NTE). Information was gathered from multiple sources using cross-referencing. The bottom three rows of data were estimated in this study using equations discussed in the text.
3.3. Physical Nature of ATE / GHE
Our analysis of interplanetary data in Table 1 found no meaningful relationships between ATE (NTE) and variables such as total absorbed solar radiation by planets or the amount of greenhouse gases in their atmospheres. However, we discovered that NTE was strongly related to total surface pressure through a nearly perfect regression fit via the following nonlinear function:
where Ps is in Pa. Figure 5 displays Eq. (7) graphically. The tight relationship signals a causal effect of pressure on NTE, which is theoretically supported by the IGL (see & 3.1). Also, the Ps–NTE curve in Fig. 5 strikingly resembles the response of the temperature/potential temp. (T/θ) ratio to altitudinal changes of pressure described by the well-known Poisson formula derived from IGL (Fig. 6). Such a similarity in responses suggests that both NTE and θ embody the effect of pressure-controlled adiabatic heating on air, even though the two mechanisms are not identical. This leads to a fundamental conclusion that the ‘Natural Greenhouse Effect’ is in fact a Pressure-induced Thermal Enhancement (PTE) in nature.
NTE should not be confused with an actual energy, however, since it only defines the relative (fractional) increase of a planet’s surface temperature above that of a SPGB. Pressure by itself is not a source of energy! Instead, it enhances (amplifies) the energy supplied by an external source such as the Sun through density-dependent rates of molecular collision. This relative enhancement only manifests as an actual energy in the presence of external heating. Thus, Earth and Titan have similar NTE values, yet their absolute surface temperatures are very different due to vastly dissimilar solar insolation. While pressure (P) controls the magnitude of the enhancement factor, solar heating determines the average atmospheric volume (V), and the product P×V defines the total kinetic energy and temperature of the atmosphere. Therefore, for particular solar insolation, the NTE factor gives rise to extra kinetic energy in the lower atmosphere beyond the amount supplied by the Sun. This additional energy is responsible for keeping the Earth surface 133K warmer than it would be in the absence of atmosphere, and is the source for the observed 44% extra down-welling LW flux in the lower troposphere (see &2.1 C). Hence, the atmosphere does not act as a ‘blanket’ reducing the surface infrared cooling to space as maintained by the current GH theory, but is in and of itself a source of extra energy through pressure. This makes the GH effect a thermodynamic phenomenon, not a radiative one as presently assumed!
Equation (7) allows us to derive a simple yet robust formula for predicting a planet’s mean surface temperature as a function of only two variables – TOA solar irradiance and mean atmospheric surface pressure, i.e.
Figure 5. Atmospheric near-surface Thermal Enhancement (NTE) as a function of mean total surface pressure (Ps) for 8 celestial bodies listed in Table 1. See Eq. (7) for the exact mathematical formula.
Figure 6. Temperature/potential temperature ratio as a function of atmospheric pressure according to the Poisson formula based on the Gas Law (Po = 100 kPa.). Note the striking similarity in shape with the curve in Fig. 5.
where NTE(Ps) is defined by Eq. (7). Equation (8) almost completely explains the variation of Ts among analyzed celestial bodies, thus providing a needed function to parse the effect of a global pressure change on the dependent variables ρ and Tsin Eq. (6). Together Equations (6) and (8) imply that the chemical composition of an atmosphere affects average air density through the molecular mass of air, but has no impact on the mean surface temperature.
4. Implications of the new ATE Concept
The implications of the above findings are numerous and paradigm-altering. These are but a few examples:
Figure 7. Dynamics of global temperature and 12-month forward shifted cloud cover types from satellite observations. Cloud changes precede temperature variations by 6 to 24 months and appear to have been controlling the latter during the past 30 years (Nikolov & Zeller, manuscript).
A) Global surface temperature is independent of the down-welling LW flux known as greenhouse or back radiation, because both quantities derive from the same pool of atmospheric kinetic energy maintained by solar heating and air pressure. Variations in the downward LW flux (caused by an increase of tropospheric emissivity, for example) are completely counterbalanced (offset) by changes in the rate of surface convective cooling, for this is how the system conserves its internal energy.
B) Modifying chemical composition of the atmosphere cannot alter the system’s total kinetic energy, hence the size of ATE (GHE). This is supported by IGL and the fact that planets of vastly different atmospheric composition follow the same Ps–NTE relationship in Fig. 5. The lack of impact by the atmospheric composition on surface temperature is explained via the compensating effect of convective cooling on back-radiation discussed above.
C) Equation (8) suggests that the planet’s albedo is largely a product of climate rather than a driver of it. This is because the bulk of the albedo is a function of the kinetic energy supplied by the Sun and the atmospheric pressure. However, independent small changes in albedo are possible and do occur owning to 1%-3% secular variations in cloud cover, which are most likely driven by solar magnetic activity. These cloud-cover changes cause ±0.7C semi-periodic fluctuations in global temperature on a decadal to centennial time scale as indicated by recent satellite observations (see Fig. 7) and climate reconstructions for the past 10,000 years.
Figure 8. Dynamics of global surface temperature during the Cenozoic Era reconstructed from 18O proxies in marine sediments (Hansen et al. 2008).
Figure 9. Dynamics of mean surface atmospheric pressure during the Cenozoic Era reconstructed from the temperature record in Fig. 8 by inverting Eq. (8).
D) Large climatic shifts evident in the paleo-record such as the 16C directional cooling of the Globe during the past 51 million years (Fig. 8) can now be explained via changes in atmospheric mass and surface pressure caused by geologic variations in Earth’s tectonic activity. Thus, we hypothesize that the observed mega-cooling of Earth since the early Eocene was due to a 53% net loss of atmosphere to Space brought about by a reduction in mantle degasing as a result of a slowdown in continental drifts and ocean floor spreading. Figure 9 depicts reconstructed dynamics of the mean surface pressure for the past 65.5M years based on Eq. (8) and the temperature record in Fig. 8.
5. Unified Theory of Climate
The above findings can help rectify physical inconsistencies in the current GH concept and assist in the development of a Unified Theory of Climate (UTC) based on a deeper and more robust understanding of various climate forcings and the time scales of their operation. Figure 10 outlines a hierarchy of climate forcings as part of a proposed UTC that is consistent with results from our research as well as other studies published over the past 15 years. A proposed key new driver of climate is the variation of total atmospheric mass and surface pressure over geological time scales (i.e. tens of thousands to hundreds of millions of years). According to our new theory, the climate change over the past 100-300 years is due to variations of global cloud albedo that are not related to GHE/ATE. This is principally different from the present GH concept, which attempts to explain climate changes over a broad range of time scales (i.e. from decades to tens of millions of years) with the same forcing attributed to variations in atmospheric CO2 and other heat-absorbing trace gases (e.g. Lacis et al. 2010).
Earth’s climate is currently in one of the warmest periods of the Holocene (past 10K years). It is unlikely that the Planet will become any warmer over the next 100 years, because the cloud cover appears to have reached a minimum for the present levels of solar irradiance and atmospheric pressure, and the solar magnetic activity began declining, which may lead to more clouds and a higher planetary albedo. At this point, only a sizable increase of the total atmospheric mass can bring about a significant and sustained warming. However, human-induced gaseous emissions are extremely unlikely to produce such a mass increase.
Figure 10. Global climate forcings and their time scales of operation according to the hereto proposed Unified Theory of Climate (UTC). Arrows indicate process interactions.
6. References
Kopp, G. and J. L. Lean (2011). A new, lower value of total solar irradiance: Evidence and climate significance, Geophys. Res. Lett., 38, L01706, doi:10.1029/2010GL045777.
Kuptsov, L. P. (2001) Hölder inequality, in Hazewinkel, Michiel, Encyclopedia of Mathematics, Springer, ISBN 978-1556080104.
Lacis, A. A., G. A. Schmidt, D. Rind, and R. A. Ruedy (2010). Atmospheric CO2: Principal control knob governing earth’s temperature. Science 330:356-359.
Lindzen, R. S. and Y.-S. Choi (2009). On the determination of climate feedbacks from ERBE data. Geophys. Res. Lett., 36, L16705, doi:10.1029/2009GL039628.
McKitrick, R. R. et al. (2010). Panel and Multivariate Methods for Tests of Trend Equivalence in Climate Data Series. Atmospheric Science Letters, Vol. 11, Issue 4, pages 270–277.
Nikolov, N and K. F. Zeller (manuscript). Observational evidence for the role of planetary cloud-cover dynamics as the dominant forcing of global temperature changes since 1982.
Pavlakis, K. G., D. Hatzidimitriou, C. Matsoukas, E. Drakakis, N. Hatzianastassiou, and I. Vardavas (2003). Ten-year global distribution of down-welling long-wave radiation. Atmos. Chem. Phys. Discuss., 3, 5099-5137.
Spencer, R. W. and W. D. Braswell (2010). On the diagnosis of radiative feedback in the presence of unknown radiative forcing, J. Geophys. Res., 115, D16109, doi:10.1029/2009JD013371
Trenberth, K.E., J.T. Fasullo, and J. Kiehl (2009). Earth’s global energy budget. BAMS, March:311-323
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This post is also available as a PDF document here:
Unified_Theory_Of_Climate_Poster_Nikolov_Zeller
UPDATE: This thread is closed – see the newest one “A matter of some Gravity” where the discussion continues.
Reply to Alan D McIntire’s comment from January 2, 2012 at 8:41 am
Alan,
You address an issue which we explain at length in our full paper, but it is not discussed in details in our poster. I will elaborate on this in my official reply later this week. Basically, the Gas Law equation ρT = P M / R (Eq. 6 in our poster) cannot be solved for T alone, because we have one equation with two unknown (T and ρ). Solving this requires a SECOND equation, which is provided by the planetary regression curve relating T to P in our Eq. (7) and more specifically by Eq. (8). Combining Equations (6) and (8) with a third equation that defines surface pressure as a function of atmospheric mass (Ma), planet surface area (A), and gravity (g), i.e. P = g Ma / A, results in a 3-equation model with the following chain of causality:
1) Pressure (P) is a function of total air mass, planet surface area, and average gravity;
2) Surface air temperature (T) is a function of TOA solar irradiance and average atmospheric surface pressure (Eq. 8);
3) Near-surface air density (ρ) depends on the mean temperature and atmospheric pressure (Eq. 6);
This implies that air density does NOT control surface temperature, atmospheric pressure does! Instead, density is a function of temperature, which is maintained by pressure and solar heating. This is a critical difference from the concept of Hans Jelbring! That is because the volume (density) of the atmosphere increases or decreases depending on the energy content of the system, while surface pressure is constant. On a planetary scale, the average thermodynamic process at the surface is ISOBARIC in nature (see Section 3.1 in our poster). Hence, temperature is INDEPENDENT of atmospheric composition, while air density is affected by that composition through the molecular mass of air (M)… It all fits together perfectly! Wouldn’t you agree? … 🙂
Ned Nikolov says:
If you don’t let minor details like conservation of energy bother you!
Folks, as I watch this discussion I keep seeing people get lost in the details. Stand back and look at the big picture.
N&Z have provided a formula that appears to have predictive skill. One CANNOT falsify it by arguing the details! Sure radiative absorption and re-emission happens in a certain way. Sure convection happens in a certain way. Sure lapse rate works in a certain way.
So What?
If there is one thing we’ve learned over the last few years of the climate debate it is (or should be) that our understanding of the mechanisms and how they interact with one another is woefully incomplete. If we were anywhere near to understanding all the pieces of the puzzle and how they fit together, we’d have climate models with predictive skills coming out the yin yang. But the fact is we don’t.
I liken this discussion to being given a pail full of gravel and being asked to determine the weight of the gravel. I could thoroughly mix the gravel, extract a representative sample, weigh each rock, pebble and grain of sand, extrapolate the expected change in distribution of the rocks, pebbles, and sand from top of the bucket to the bottom of the bucket based on known paramaters for the settling of gravel over time, and from there arrive at an estimate of the weight of the gravel in the pail.
Or I could weigh the gravel and the pail, then pour the gravel out, and weigh the pail.
What N&Z are purporting to do is the latter. One cannot falsify their results by arguing about what the proper distribution of grains of sand is or how gravel does or does not settle when poured into a pail. The only way to determine if they are on to something is to weigh the gravel.
What they have said is that for a given TOA radiance, and a given mean surface atmospheric pressure, they can calculate the average surface temperature of a planet. They’ve even published their predictions for no less than EIGHT planetary bodies!
The only question we should be interested in at this point (it seems to me) is this:
Did they get the surface temps of those planetary bodies right or not?
If no, then their formulas are wrong.
If yes, then it seems to me there are only two possibilities.
1. Their formulas are correct, we just don’t know exactly WHY they are correct.
or
2. They successfully predicted the surface temps of 8 celestial bodies by coincidence.
If the latter, that’s one awfull big coincidence!
So, would it not make sense to dispense with the arguments about the life time of a photon in earth atmosphere, how convection changes with pressure, what absorption bands various gases have and just answer the question:
Did they nail the temps of those planetary bodies? Or not?
Ned Nikolov:
At January 2, 2012 at 9:44 am you say:
“This implies that air density does NOT control surface temperature, atmospheric pressure does! Instead, density is a function of temperature, which is maintained by pressure and solar heating. This is a critical difference from the concept of Hans Jelbring!”
Yes, it is a “critical difference”. But it is not obvious and I (for one) missed it. Thankyou for pointing it out.
I write to ensure that your point is emphasised.
Richard
Joel Shore:
Your post at January 2, 2012 at 10:44 am says;
“Ned Nikolov says:
\It all fits together perfectly! Wouldn’t you agree? … 🙂
If you don’t let minor details like conservation of energy bother you!”
Please explain in what way you think anything Ned Nikolov wrote contradicts conservation of energy?
Your failure to provide this explanation would show you to be making an even bigger ass of yourself than you have already repeatedly achieved in this thread.
Richard
Joel
I understand your worry about the conservation of energy. What is coming in as energy from the sun, has to go out at the top of the atmosphere.(TOA) But if the atmosphere as an intermediate between TOA and surface, had gained over time a particular temperature, with a specific density- and temperature- gradient, from surface to TOA, then the law of conservation of energy would not necessarily be violated, if incoming energy from the sun still equals what is going out at the TOA. Could you explain where you see the law violated?
Give another thought the fact that the entropy of the incoming quanta (visible light) is different from the out going (IR). The system as a whole is not in at thermodynamic equilibrium (maximum entropy status). The consequence is that some ‘order’ is maintained. (Like in a living cell). What kind of order would you expect? I guess the maintenance of a gradient. With a higher temperature at the surface than at the TOA.
Joel Shore, I noticed your arguments were completely dismantled on Judith Curry’s blog. Still singing the same old song though. Hope you are not a representative sample of academic thinking.
A side line
IPCC produces a report WG1, named the ‘scientific base’. In the current draft for AR5 it is claimed that there is increasing evidence for CO2 increasing global warming. However, I do not see evidence for that presented in this draft. And no arguments, as presented on this blog, are (of course) mentioned on the disputed ‘greenhouse effect’. Rather then comment on the thousands of issues in the draft, I have chosen for the preparation of a manuscript entitled:
‘A warning, there is insufficient scientific evidence in draft WG1 AR5’ with emphasis on some science philosophical issues which underlie modern natural sciences. (E.g. complexity theory)
I would like to subject this manuscript for peer-review among them who are reading the draft. Just to check whether I made mistakes in my analysis. Who is prepared to referee?
I am not waiting for emotional comments, nor that much ‘facts from figures’ The latter will be produced by critical expert reviewers, which are allowed by IPCC to do so. I want the basic principle of the ‘scientific base’ be discussed .
Arthur@keykey.nl
Terry Oldberg,
Thanks for helping to tidy up terminological issues.
I took your earlier point that both the radiative greenhouse effect and the gravitationally induced greenhouse effect can both be regarded as thermodynamic processes. I picked up a bad example from someone else in attaching the term ‘thermodynamic’ only to the latter.
Your suggested refinement of terminology for the so called back radiation is also very helpful. I had been struggling with a way of saying that it does not exist without being accused of some sort of denialism. Your suggestion now means that I can say that there is no NET downward heat flux (because the net flux is always upward) so that the term ‘back radiation’ is misleading even though there is a downward flow from atmospheric molecules radiating in all directions.
I think N & Z are correct if what they are saying is that what is termed ‘back radiation’ is actually just the temperature of the near surface air molecules AFTER the GHGs higher up have had their effect in reducing the upward flow of energy.
Arthur Rörsch, The Netherlands (January 2, 2012 at 11:49 am):
Shore seems to be claiming that if the intensity of the back radiation increases by Delta F then the intensity of the heat flux into Earth’s surface must increase by Delta F else energy conservation is violated. However, Shore’s claim is falsified if the increase in the intensity of the back radiation is offset by a numerically equal increase in the intensity of the convective heat transfer. A mechanism that produces this result is operative in the atmosphere. It operates because any increase in the intensity of the back radiation increases the local lapse rate. If the local lapse rate grows to exceed the local adiabatic lapse rate, the state of the atmosphere is destabilized by the buoyancy of the local air column with respect to its surroundings. This column floats upward and as it does so, it
restores the local lapse rate to the adiabatic lapse rate. Thus, outside of inversion layers, the lapse rate is set by a natural feedback control mechanism to the adiabatic lapse rate. The adiabatic
lapse rate, though, is insensitive to the composition of the atmosphere. The finding of Nikolov and Zeller suggests the possibility that this feedback control mechanism dominates over fluctuations in
the intensity of the back radiation in setting the surface temperatures of planets with atmospheres.
“This implies that air density does NOT control surface temperature, atmospheric pressure does! Instead, density is a function of temperature, which is maintained by pressure and solar heating. This is a critical difference from the concept of Hans Jelbring!”
Is it a critical difference ?
Higher atmospheric pressure induced by gravity increases density at the surface so that the heat content then rises more than it would have done at a lower pressure when a given amount of solar irradiation is added. It is true that in the first instance the cause is indeed atmospheric pressure but it isn’t far out to say that the temperature rise is caused by density if it is taken as a given that the density was caused by atmospheric pressure.
“Terry Oldberg says:
January 2, 2012 at 1:01 pm”
“The finding of Nikolov and Zeller suggests the possibility that this feedback control mechanism dominates over fluctuations in the intensity of the back radiation in setting the surface temperatures of planets with atmospheres.”
Agreed, just as I have been pointing out for the past 4 years.
However there is a miniscule climate effect because the process of negating the effect of non condensing GHGs involves a change in the speed or size of the water cycle which alters the surface air pressure distribution a fraction.
It couldn’t be measured as against natural variations induced by sun and oceans though.
Terry Oldberg:
At January 2, 2012 at 1:01 pm you say to the venerable and erudite Arthur Rörsch (whose presence here we should all welcome):
“ Shore seems to be claiming that if the intensity of the back radiation increases by Delta F then the intensity of the heat flux into Earth’s surface must increase by Delta F else energy conservation is violated. However, Shore’s claim is falsified if the increase in the intensity of the back radiation is offset by a numerically equal increase in the intensity of the convective heat transfer.”
Etc.
And you then give a detailed explanation of how the falsification occurs.
However, I do not think that can be what Joel Shore is claiming because I completely refuted that to him in my post at January 1, 2012 at 1:34 pm.
So, either
Joel Shore means something other than you think he means
or
Joel Shore is repeating what he knows to be a falsehood.
Therefore, I think we need to pressure him to clarify what he is claiming before trying to answer it. This is why at January 2, 2012 at 11:27 am I asked him;
“Please explain in what way you think anything Ned Nikolov wrote contradicts conservation of energy?”
Richard
Myrrh says:
December 31, 2011 at 3:51 pm
Robert Brown says:
December 30, 2011 at 7:19 am
Myrrh said something like “Water is transparent to visible light, therefore, visible light does not heat the oceans, for example.” What this indicates is that Myrrh should not participate in discussions with “paid scientists” unless/until he learns some basic physics.
FWIW, let’s correct this. Water is not transparent to visible light. It is simply more transparent than, say, rock.
Hmm, I prefer to go with the paid physicists who taught me..
Thermal infrared, heat energy, thermal energy on the move direct from the Sun by radiation does have the oomph to move whole molecules into vibration, to raise the temperature , to heat them up.
Those physicists must be spinning in their graves! According to Myrrh less energetic IR has enough ‘oomph’ to move whole molecules but the more energetic visible can only move electrons!
It is obvious that Richard C and I are asking for an explanation of Joel why he thinks that the ‘theory ’is violating the first law.
Thanks Ned, I’ve copied that over for Hans to respond to here:
http://tallbloke.wordpress.com/2012/01/01/hans-jelbring-the-greenhouse-effect-as-a-function-of-atmospheric-mass/#comment-12740
Richard S Courtney says:
I’ve explained it here: http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-846787
The idea is very simple: The Earth’s surface can’t be at a temperature where it radiates about 390 W/m^2 when when the Earth’ surface plus atmosphere are only absorbing 240 W/m^2 from the sun unless one or more of the following is true:
(1) It is cooling down extremely rapidly, which it is not.
(2) There is some gargantuan energy source that is supplying 150 W/m^2 of power, which nobody has identified could possibly be present.
(3) Some of the radiation emitted by the Earth’s surface is absorbed by the atmosphere.
Hence (3) is the only thing that can explain the Earth’s elevated surface temperature. And, we know in fact that (3) is what is happening because we have satellite measurements, radiative transfer calculations, and measurements of gas absorption lines that all confirm that this is the case.
The people who are making a**es out of themselves are those skeptics who are not running as fast and furiously away from this nonsense as they can. Young Earth creationists have absolutely nothing on such folks!
“Young Earth creationists have absolutely nothing on such folks!”
Making a donkey of yourself now Joel?
you have missed the point of this theory. I can tell, because you didn’t list alternatives.
4)The temperature boost at the surface due to the presence of an atmosphere constrained by a gravity well.
What you don’t seem to get is that your calcs, which you think all add up nicely to give a radiative answer actually already contain the pressure effect as well as the radiative element. The problem is you don’t understand that the presure element is dominant, and the radiative effect small.
Never mind, given the self conditioning you’ve put yourself through for these many years, you’ll probably ‘get it’ long after everybody else.
Terry Oldberg says:
“January 2, 2012 at 12:23 pm
Steve Richards (Jan. 2, 2012 at 4:13 am):
The back radiation is real but is not a heat flux. A few years ago, terminologically sloppy climatologists set off a controversy over this matter by stating incorrectly that the back radiation was a heat flux, prompting critics to point out that for heat to flow from cold to hot matter in the absense of a heat pump would be to violate the second law of thermodynamics. For a while, I thought that the second law violation invalidated AGW as a concept but I then learned that the apparent second law violation resulted only from the mislabelling of a concept by these climatologists.
The confusion can be avoided by assigning the back radiation to the class of vectors to which it belongs. This is the class of vectors that are called “vector irradiances.” At a space point in a radiation field, the radiative heat flux is the vector difference of two vectors. The first belongs to the class of vector radiosities. The second belongs to the class of vector irradiances. In the literature that was left to us by the sloppy climatologists, each of the two vectors is called a “heat flux” while their vector difference (the radiative heat flux) is called the “net radiative heat flux.”
I’ve alerted a number of professional climatologists to the terminological error and the potential for misunderstanding that is created by it without finding a single one of them who is willing to lift a finger to clean up the error.”
Thank you for your answer. I am happy that someone agrees that ‘back radiation’ in not heat producing.
However, a quick scan on google on this new term (to me) of ‘vector irradiances’ showed that climate researchers use Cosine Collectors to measure ‘vector irradiances’ which is named ‘back radiation’.
This would appear to me to be a way of squeezing more power into the GHG simulations without violating any fundamental rules of thermodynamics.
Joel Shore:
Your recent post at January 2, 2012 at 3:03 pm proves to all observers that you are so blinded by prejudice that you are incapable of admitting when you are wrong: you keep muttering your error in the hope that repetition will shout down the explanations of your error.
Your recent post says;
“The idea is very simple: The Earth’s surface can’t be at a temperature where it radiates about 390 W/m^2 when when the Earth’ surface plus atmosphere are only absorbing 240 W/m^2 from the sun unless one or more of the following is true:
(1) It is cooling down extremely rapidly, which it is not.
(2) There is some gargantuan energy source that is supplying 150 W/m^2 of power, which nobody has identified could possibly be present.
(3) Some of the radiation emitted by the Earth’s surface is absorbed by the atmosphere.”
Your point (2) was addressed by me at January 1, 2012 at 1:34 pm where I wrote e.g.
“The global energy balance is not relevant to present discussion. You are trying to pretend (to yourself?) that the discussed hypothesis denies the existence of back-radiation: it does not.”
And your point (3) was refuted by me
at December 31, 2011 at 9:39 am and
at January 1, 2012 at 1:34 am and
most directly at January 1, 2012 at 1:34 pm.
Subsequently, Terry Oldberg refuted it at January 2, 2012 at 1:01 pm where he provided a detailed and explicit explanation of why your point (3) is plain wrong.
Both Terry Oldberg and I told you that additional radiation to the atmosphere is not required for energy balance if the additional thermal transport to the atmosphere were provided by enhanced evaporation and conduction from the surface.
Indeed, I responded to Terry Oldberg’s refutation of your point (3) by saying to him:
“I do not think that can be what Joel Shore is claiming because I completely refuted that to him in my post at January 1, 2012 at 1:34 pm.
So, either
Joel Shore means something other than you think he means
or
Joel Shore is repeating what he knows to be a falsehood.”
I now make a public apology to Terry Oldberg. I was wrong to have suggested that Terry Oldberg was mistaken in his implication that you were repeating what you know to be a falsehood: your recent post states that in fact you were repeating what you know to be a falsehood.
And your recent post that I am replying does it again.
Richard
Actually, 3) Some of the radiation emitted by the Earth’s surface is absorbed by the atmosphere.
is just an incomplete version of 4) The temperature boost at the surface due to the presence of an atmosphere constrained by a gravity well.
Joel’s 3) assumes that the energy ‘absorbed’ by the atmosphere is there in the atmosphere because of the radiative characteristics of GHGs.
In fact all or nearly all of it may be there because of gravity compressing the atmosphere to create the lapse rate as per 4)
Joel previously accepted the pressure driven lapse rate as I recall.
What I want to know from a warmist proponent is:
How much of the 150 Wm2 is due to radiative effects of GHGs alone and how much due to gravitational compression of ALL the molecules in the air including Oxygen and Nitrogen ?
Then, how much of the residue of Wm2 is due to CO2 alone ?
Then, how much is due to man’s emissions alone ?
Have warmists done those calculations in the models or have they not ?
Joel says nothing about gravitational pressure here:
“we have satellite measurements, radiative transfer calculations, and measurements of gas absorption lines that all confirm that this is the case.”
Richard S Courtney says:
What it claims is that one can calculate the surface temperature knowing only the surface pressure and the solar irradiance. Since it is possible in principle to have an atmosphere that is essentially transparent to IR radiation, this means that an Earth with an atmosphere transparent to IR radiation, having the same surface pressure would have the same surface temperature. And, this notion indeed violates energy conservation.
As I have explained to you again and again, an earth with a hypothetical IR-transparent atmosphere would be emitting back out into space more radiation than it absorbs. You cannot remedy this by transferring additional energy away from the Earth. It only makes the “deficit” worse.
Stephen Wilde says:
Stephen: This makes no sense. How is gravity supplying 150 W/m^2 of power? Gravity cannot supply energy unless the gravitational potential energy of the Earth and its atmosphere is decreasing.
It is all due to radiative effects. Gravitational compression does not supply energy unless the Earth and its atmosphere are undergoing gravitational collapse so that gravitational potential energy is being converted into other forms of energy. That is not happening.
Let me take a shot at clarification — using a variety of gedanken experiments. I’ll give my conclusions (which have actually sharpened considerably as I wrote this). .
In each case we will start with a barren world with no water (and consequently no clouds), somehow “painted” so that the albedo is 0.3 (absorption = 0.7 for incoming solar radiation) and the IR emissivity is 1.0. I will also assume the rotation rate and thermal conductivity are large enough that temperatures are fairly constant over the surface. This simplifies the discussion with becoming completely unphysical, (At least in my opinion. In any case, this correction could be added later when analyzing in more detail.)
Also, let me define two components that contribute to the temperature of the atmosphere and the surface (ie these combine to produce “the greenhouse effect”).
* RTE (radiative thermal effect) of the atmosphere as the direct effect of the IR absorption/emission in the atmosphere. This effect attempts to bring different parts of the atmosphere to the same temperature.
* GTE (gravitational thermal effect) of the atmosphere, due to changes in potential energy with altitude. This effect tries to create a temperature gradient of ~ 10 K/km as altitude increases (ie the “dry adiabatic lapse rate” = DALR).
1) No atmosphere. I conclude the “average surface temperature” would be ~ 255 K, as required by Stephan-Boltzmann calculations.
2) A pure N2 atmosphere similar in mass to earth’s atmosphere, which we will assume is perfectly transparent. There is no RTE. The GTE will cause the temperature to DROP by 10 K/km STARTING FROM 255 K at the surface.
There is no enhancement of the surface temperature.
3) A thin glass shell at an altitude of 1 km (but no atmosphere). This shell is perfectly transparent to sunlight (wavelength 4 um). A total of 240 W/m^2 is still absorbed, and 240 W/m^2 must radiate. This 240 W/m^2 will all radiate from the glass shell (and thermal radiation from the ground will get blocked by the the shell on the way up). RTE will try
There is STILL no enhancement of the surface temperature.
4) A glass shell AND an N2 atmosphere. Again, the shell will have to be at 255 K. The RTE will try to keep the ground at 255K, but the GTE will try to keep the ground at 265 K (due to the 10 K/km adiabatic lapse rate). The true average temperature must be somewhere in between, and the true lapse rate (TLR) must be 0 < (TLR) < DALR. (This agrees with Joel's intuition and my intuition.) For the sake of argument, assume the TLR is 5 K/km (although I suspect it would be higher); the surface temperature would be 260 K.
An enhancement of the surface temperature requires BOTH RTE and GTE!
4B) Raise the shell to an altitude of of 2km. The shell at 2 km would be at 255 K to radiate enough energy, and the ground would be T = 255 K + TLR*2 = 265 K.
4C) Shells at both 1 km and 2 km. The top shell will still be 255 K (as in 4B). The middle shell will be 255 K + TLR = 260 K. The surface will be 260 K + TLR = 265 K.
Intermediate shells make no difference! Any “saturation of IR absorption” between the ground and the TOA (top of atmosphere) is of little/no importance. Only the radiation from the TOA sets the temperature at the ground in this gedanken experiment.
5) A shell at 2 km, but it only blocks 1/2 of outgoing “earthshine” (more like real GHGs). The RTE will be reduced because there is less IR flying around to equilibrate the land and the TOA, So the TLR will be larger than in (4); let’s call it 8 K/km. Some outgoing IR will come from the ground & some will come from the TOA.
If my numbers are right, then the TOA will be 246.5 K and the surface will be 262.6 K. This is less than before in (4B), which makes sense because we have a reduced RTE ie a reduced “greenhouse effect” from less IR absorption.
—————————————–
NOTE: this is not a “new theory” of climate. It is taking bits of N&Z’s approach and (hopefully) more properly accounting for the need for IR absorption in the atmosphere to obtain a true “GHE”.
Of course, there are endless refinements that could be made, but I think this shows why there is a need for both the “RTE” and “GTE” in the “GHE”.
Tim Folkerts says:
Tim: Actually, I think you start to go astray here. The glass shell is essentially a blackbody shell for terrestrial radiation (and transparent to solar radiation). Hence, what you have is one of the very simplest models of the greenhouse effect, in fact the one shown in Fig. 1 above. The glass shell will radiate 240 W/m^2 up and 240 W/m^2 down. The Earth’s surface will radiate 480 W/m^2 up and hence will be at an elevated temperature of 255K * (fourth root of 2) = 303 K. [Note that because of the lack of an atmosphere, there is no convection to worry about…It is purely a radiative problem.]