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.
Joel Shore:
At January 1, 2012 at 6:50 am you ask me:
“(1) How do radiative effects adjust themselves?”
I answer, they don’t. They adjust in response to various changes (i.e. temperature, humidity, etc.).
Then your post makes a platitude about lapse rates.
And you follow that with complete twaddle which proves you have completely failed to understand the hypothesis being discussed. We are attempting to evaluate that hypothesis with a view to determining whether it should be accepted, rejected or amended. Please try to understand the hypothesis because your twaddle disrupts sensible discussion.
An example of the twaddle is provided by your having written;
“As I have explained, you can’t evoke evaporation and conduction because the extra 150 W/m^2 that I am talking about means that the planet’s surface is already emitting more energy than it could if there were not a greenhouse effect. Evaporation and conduction only make the problem worse, unless you are proposing that evaporation and conduction transfer 150 W/m^2 FROM the atmosphere TO the surface!”
This is so wrong that one could write a book on its errors.
For simplicity, I will point out only one of them.
Evaporation occurs (if you dispute this then explain how rain happens).
And evaporation cools the surface.
Increase evaporation and the surface cooling increases.
Reduce evaporation and the surface cooling reduces.
Please explain how evaporation “makes the problem worse”. What problem? And how could either an increase or reduction to evaporation fail to provide a possible reduction to it?
Richard
I’ve notice I’ve made the same typing error here as I made in another discussion, making the Earth with atmosphere but without the water cycle read ‘minus’ 67°C
http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-846626
Myrrh says:
December 29, 2011 at 5:16 am
We’ve always had a unified theory of climate. The general figure as given as I’ve seen it is that the whole of the atmosphere is Earth’s greenhouse and therefore all the gases in it are greenhouse gases, predominantly nitrogen, oxygen and water.
Without the atmosphere the Earth would be -18°C, but, it only gets the +33°C warming to 15°C via the dynamics of all the greenhouse gases –
without any atmosphere -18%deg;C
with atmosphere but minus the Water Cycle – 67°C
The water cycle cools the Earth by 52°C
– to bring it down to the 15°C from the 67%deg;C it would be with the main greenhouse gaseous ocean of nitrogen and oxygen above us, pressing down on us a ton/square foot.
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The bold should read:
without any atmosphere: -18°C
with atmosphere but minus the water cycle: 67°C
=============================
Sorry.
Richard S Courtney says:
What it makes worse is the problem that you are faced with in achieving energy balance in the absence of the atmospheric greenhouse effect. And, the reason why a reduction in evaporation won’t help you is that it can’t be reduced to a negative value.
You appear to be describing your own comments.
Can you even recognize why your statement is not science at all?
D. Patterson: Your comment adds absolutely nothing to the scientific discussion and are thus not worthy of any response.
@Dale Rainwater. bill
> The derivation is at the link I gave earlier, and it’s in every
> Physics book on the subject, going back forever.
> Click on the “Show” button to get the details. I’m done with it…
Ok, I think I see the problem here, dr. bill is referring to the simplified “ideal” (monatomic-like) gas model, where by definition only translational energy is considered. Indeed, there is a HyperPhysics disclaimer stating such below the “Show” button:
And even when rotation and vibration are accounted for under the equipartition theorem, it is a common practice to simplify the model by treating all degrees of freedom as “uncoupled”, i.e. no interaction between the degrees of freedom. Under such simplifying assumptions rotation/vibration have no effect on translational energy. Physicists are entitled to make these simplifying, “first-order” approximations, in order to get their heads around complex concepts, such as radiation transfer and thermal equilibrium.
But in the the real world, translation, rotation and vibration can be coupled together, such that (for example) absorbed vibrational energy (e.g. IR photon absorbed by CO2 molecule) can be coupled (“equipartitioned”, “thermalized” etc) to translational energy and thus enhance the translational kinetic energy.
Here is Tom Vonk’s summary of these coupling options:
http://wattsupwiththat.com/2010/08/05/co2-heats-the-atmosphere-a-counter-view/
Yes, it’s true that translational energy dominates the diffusion of thermal energy (“heat transfer”), in order to solve the heat equation with finite differentials in the x,y,z directions. But rotation and vibration still must be considered in calculating the heat capacity of real world gases. And they can transfer molecular momentum directly to the diffusion process. (Energy and momentum must always be preserved. “Vibrating molecules” are essentially collections of atoms in motion)
Yes, the effects of these DOF’s vary, according to temperature, density, polarization etc, so for certain configurations one or more DOF’s may be declared “frozen out” or ignored as “neglible”.
Or not.
Bottom line: it is incorrect to assert as an absolute principle (as dr. bill did) that “only translational energy is involved in determining temperature”
It seems to me that contributors to this thread have jointly made progress on the issue of the significance of the conjecture of Drs. Nicolov and Zeller (N&Z). It has been shown that a violation of energy conservation does not lie in N&Z’s conjecture when it is made conjunction with the radiative emission of 390 W/m^2 at Earth’s surface and radiative emission of only 239 W/m^2 at the top of the atmosphere, contrary to the assertion of Joel Shore. In claiming violation of energy conservation, Shore seems to have overlooked the fact that 239 W/m^2 is the intensity of a heat flux while 390 W/m^2 is the intensity of a radiative energy flux making this an apples vs. oranges comparison. At Earth’s surface, the heat flux is the vector sum of an upward pointing vector with an intensity of 390 W/m^2 and a number of other vectors each representing a flux of energy. According to Trenberth et al(2008), over the period from March 2000 to May 2004 the vector sum of these vectors was 238 W/M^2. The difference between the intensities of the heat fluxes at the bottom and top of the atmosphere, – 1 W/M^2, was absorbed by the land and oceans with the result that energy was conserved.
Among the vectors representing fluxes of energy at Earth’s surface is the one which Trenberth et al label the “back radiation.” According to Trenberth et al, it had an intensity of – 333 W/m^2. This vector is expected to grow in its absolute intensity with increases in the concentrations of greenhouse gases in the atmosphere. If a rise in this intensity were the sole response from increases in these concentrations then the equilibrium temperature at Earth’s surface would have to rise in response for energy conservation. However, a rise in the absolute intensity of the back radiation is NOT the sole effect from increases in greenhouse gas concentrations.
According to Trenberth et al, in the period between March 2000 and May 2004 convective heat transfer with an average intensity of 17 W/m^2 was operative at Earth’s surface. Wherever there was convective heat transfer in the atmosphere with a positive intensity, this was sufficient to have set up a feedback loop that persistently forced the lapse rate toward the adiabatic lapse rate. In these regions, the rate of decline of the atmospheric temperature with altitude was set by the adiababic lapse rate and not by the the intensity of the back radiation. The adiabatic lapse rate was insensitive to the concentrations of greenhouse gases but sensitive to the pressure at Earth’s surface. Thus, contrary to the implied claim of Shore, the existence at Earth’s surface of back radiation of a positive intensity does nothing to invalidate the conjecture of N&Z.
Shore correctly observes that the lapse rate determines the surface temperature only to within an integration constant. If there is an effect of variations in the concentrations of the various greenhouse gases upon the surface temperature then it must be manifested in the numerical value of this constant.
Let this constant be represented by the function f(P, C1, C2…) where the variables C1, C2… designate the concentrations of the various greenhouse gases and let P designate the surface pressure. Let TL(P) designate the result from integrating the adiabatic lapse rate from the surface up into the atmosphere in regions in which convective heat transfer was operative. Let TS designate the surface temperature. The mechanism already described suggests it as approximately true that
TS(P, C1, C2…) = TL(P) + f(P, C1, C2…)
The above equation clarifies the significance of the work of N&Z by separating the surface temperature into the additive effects of a term that varies only with the surface pressure, TL(P), and the residual term, f(P, C1, C2…). The residual term is observable as scatter about the function TL(P).
The work of Nicolov and Zimmer advances global climatology by suggesting: a) a functional form for TL(P) and b) bounds on the magnitude of f(P, C1, C2…) under wide variations in the CO2 concentration. As Shore points out, the conclusions of N&Z are based upon a curve fit in which there were many free parameters but few observations of the values of the variables. When a model is generated in this manner it is especially prone to error. Thus, as always, the conclusions of N&Z should be tested with reference to sufficient observed events not employed in the construction of their model for the statistical significance of their finding (or lack of same) to be demonstrated.
Joel Shore:
Thankyou for your post at January 1, 2012 at 11:12 am that answers my questions; viz.
“Please explain how evaporation “makes the problem worse”. What problem? And how could either an increase or reduction to evaporation fail to provide a possible reduction to it?”
Your answer says;
“What it makes worse is the problem that you are faced with in achieving energy balance in the absence of the atmospheric greenhouse effect. And, the reason why a reduction in evaporation won’t help you is that it can’t be reduced to a negative value.”
Oh dear, NO!
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 the energy balance does reduce “to a negative value” at the poles.
The tropics are net absorbers of radiation and the poles are net emitters of radiation.
I do genuinely appreciate your answers to my questions because they confirm my suspicion that your “problem” only exists in your imagination.
But, importantly, and of course, none of this consideration of your imaginary problem adds anything to our ability to accept, reject or amend the hypothesis being assessed in this thread.
Richard
Your inability and/or flat refusal to consider the errors in your assumptions demonstrates how you are engaging in a non-scientific discussion. The above quote of your statement focuses in part on your comment “the lapse rate in an atmosphere strongly heated from below and cooled from above is close to the adiabatic lapse rate[….].
The problem with your comments is the way in which you erroneously assume the unrealistic conditions of an idealized model exist in the real world. You talk about “lapse rate” and adiabatic lapse rate” as they exist in the idealized model without observing how the real world often does not exhibit such behavior. Now, if that isn’t scientific enough for you, it can only be concluded that you are living on the other side of the mirror in Alice’s Wonderland.
John Day, January 1, 2012 at 1:01 pm :
OK, I guess I’m not done with it. 🙂
John: At the risk of sounding pedantic, let me reiterate that there is no approximation, first-order or otherwise, involved in the definition of temperature in terms of Translational Kinetic Energy. That’s simply what it is, and this has nothing to do with the fact that energy can be absorbed by molecules via their other energy modes, such as rotations and vibrations, which do contribute to the heat capacity, just as do the translational modes, but do not contribute to the temperature while the energy is still in one of those other modes.
None of that, however, precludes the possibility of having energy that is initially absorbed, for example, in a rotational mode, get “converted” to translational energy via various interactions. That is precisely what happens when you heat something in a microwave oven.
My original point, which seems to have been missed altogether, was that this kind of “conversion” might actually be more likely under higher pressure or density conditions in a gas, just as it is in a liquid (which you might think of as a super-dense gas), and could thus be an argument in support of the “enhancement” that Nikolov and Keller are proposing. I don’t know if that is really the case, but to me it points in that direction.
I think we’ve simply been in “violent agreement”. 🙂
/dr.bill
dr.bill says: (and John Day)
January 1, 2012 at 2:56 pm
My original point, which seems to have been missed altogether, was that this kind of “conversion” might actually be more likely under higher pressure or density conditions in a gas, just as it is in a liquid (which you might think of as a super-dense gas), and could thus be an argument in support of the “enhancement” that Nikolov and Keller are proposing. I don’t know if that is really the case, but to me it points in that direction.
>>
Very good point dr.bill! I missed that somewhere above, and you are correct. This thermalization occurs due to collisions and the number of collisions has to do with density and N&Z are saying that the only free parameter is density in relation to temperature. Now that you, John Day and I are all well versed in this area and appear to be parallel, we should collective help to answer the very next question.
Look at Venus, the pressure is set by the mass, 92 times Earth’s. BUT, density is just 65 times and the molar mass ratio is ~44/29 which does calculate very close to Venus’s mean surface temperature. Why?
The closest I have come is that it seems to have a tie to the “mass extinction coefficient” of substances. The more mass, the more absorption, therefore, more internal energy which will, by equipartition, thermalize, not all as I said above dr.bill, but a ratio related to specific heat, and through density show as temperature for pressure can’t change, and lo and behold, the temperature does match. Why ‘o why does this pressure/density/molar mass end up correct on so many other bodies temperatures?
That tends to say the “mass extinction coefficient” supplies secondarily the energy to have the correct density at all times and every altitude level by first principles. But I can’t seem to tie that down so far.
Let me see if I can summarize in one long string: Assuming a planet’s atmosphere has a preference point any increase in temperature above that would increase the volume and lower the density giving a thinner atmosphere everywhere allowing radiation to escape easier which would lower the temperature. If temperature decreased the opposite would occur. An atmospheric thermostat or a radiative pressure relief vale so to speak. That kind of logic. Now to find if that does in fact occur by simple first principles. I tend to think it is that simple. Physics loves symmetry and simplicity.
Both of you, please help here if possible, we might be able to help others understand this very non-intuitive relation. (or we can just wait a week for N&Z’s more detailed description that might answer that)
What I see is serious and knowledgeable people considering the implications implied in the hypothesis.
Consideration is not indicative of the faith required for belief. Faith and belief are internal processes that are best discussed with a therapist or as in your case, a high AGW priest.
Your arguments did sharpen the discussion as your every point was dismantled to it’s arm waving core. Scientific nonsense should be easily demonstrated as such. I am still waiting to read your demonstration (hopefully one that does not include evolution). GK
The is no such thing as back radiation
Heat energy travels from hot to cold.
Lets assume the surface of the earth and the atmosphere close to it are at 288K and the top of the atmosphere is at 3K, There will (excluding temporary anomalies, density and gravity etc.) be a linear fall of measurable temperature from surface to space.
Molecules at 288K will be in contact with adjacent molecules of a lower temperature/energy level. The radiative energy from the 288K collection will transfer energy to these less energetic colleges, increasing their energy level, causing them to increase their radiation.
The newly energised molecules have “used up” so of the original energy.
the newly energised molecules will have a temperature/radiation output somewhat lower than 288K.
This process will continue until all/most of the energy has been used up transferring from molecule to molecule, cooling along the way until the edge of atmosphere is reach and the final, outer layer are at 3K.
Nowhere is energy returning to the surface of the earth!
In this scenario, the earth is warm, space is cold.
If we could, in some way, impede the flow of energy from earth to space, what would happen?
Perhaps by introducing a change in the gas mix, the insulation effect of the atmosphere was enhanced. We would see the temperature of the earth/atmosphere interface increase to a level that gives sufficient increase to the earth/space temperature gradient.
The larger the temperature gradient, the greater the energy/heat flow.
As an aside, as gases warm their thermal conductivity increases, increasing heat/energy flow, whic could help explain some of the self regulating aspects of our planet.
S.
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.
Joel Shore says:
January 1, 2012 at 10:11 am
It does not illustrate that the science is unsettled any more than similar debate on a creationist website illustrates how unsettled the science of evolution is.
The quality of your argumentation doesn’t seem to be evolving. In fact, you seem to be turning into a knuckle dragger. Hoist those hams and block your ears or cover your eyes with them Joel. Best of all, use them to cover your mouth and save yourself further embarrassment.
“Steve Richards says:
January 2, 2012 at 4:13 am
The is no such thing as back radiation
Heat energy travels from hot to cold.
”
Think about it again!
2nd law (and common sense) is referring to net amount of heat flowing from cold to hot doesn’t happen. Net heat only flows from hot to cold. However, radiative transfer, the emission of radiation occurs all the time for objects above 0K and the object radiating has no knowledge of what the temperature is of what might be surrounding the object and absorbing that radiation so the object has no clue it shouldn’t radiate. Hence an object with emissivity = 1 at a temperature of 288k will emit 390 Watts from every meter^2 of its surface according to Stefan’s law. If the object is in a box whose sides have emissivity =1 that is at a temperature of 0k, then the object will radiate 390 W from each square meter of surface area and receive no power radiating back from the box. This will last until the object cools down to 0K and reach thermal equilibrium (which also means less radiation as it cools over time).
If the sides of the box are at 288k, the object will still radiate 390 W /m^2 but since the object is in thermal equilibrium with the sides of the box, there can be NO NET flow of heat in or out of the object as that would change its temperature and would cause the loss of thermal equilibrium. That means the object will receive 390 W/m^2 of power as well as radiating 390 W/m^2.
If the sides of the box are at 500k, the object will still radiate 390 W/m^2 but the sides of the box will be radiating about 1240 W/m^2 and there will be a net heat transfer from the sides of the box to the object until the object has warmed to 500k and it finally is radiating at 1240 W/m^2 and thermal equilibrium has been reached again.
No violation of 2nd law. No change of thermal emission rate for a fixed temperature. No NET flow of heat from cold to hot even though there is power flowing both directions.
Joel Shore says:
January 1, 2012 at 7:04 am
cba says:
Joel,
Look at this again! They integrate over a hemisphere (0 – 1 for u= cosTHETA and 0-2pi for phi and they divide by 4*pi – the area value for a unit radius sphere. Theta ranges from 0 to pi/2, not 0 to pi.
Okay…I am beginning to believe that you are right. It looks like they have made multiple errors in their calculation:
(1) The factor of 2 error that you note.
Why not have a go at refuting Hans Jelbring’s similar conclusions, proven using a model earth which does not have the spinning – illuminated from one side issue to deal with:
http://tallbloke.wordpress.com/2012/01/01/hans-jelbring-the-greenhouse-effect-as-a-function-of-atmospheric-mass/
tallbloke, thanks for the link. Jelbring specifically says that climate change is not caused by mass change which is opposite to the UTC’s (junk) proposition. He also defines Greenhouse Effect as the temperature difference between the radiating level and surface (like Postma did). This is not a good way to remove the effect of greenhouse gases because the radiating level depends on their distribution. If there are none, the radiating level is the surface. If there are GHGs like for earth, it radiates from throughout the atmosphere, depending on wavelength but averaging 5 or more km globally. So, conversely to Jelbring, GHGs do determine temperature via affecting he radiating level, and a higher radiating level means a warmer surface because there is a lapse rate set by convection.
Jim, long term climate change would be affected mass changes under Jelbring’s scheme. Non-condensing GHG’s may affect the radiating level. Just not very much…
Nikolov and Zeller suggest that there is no back radiation, just the temperature of the air above the surface. I agree and this is why.
We do not need the non condensing GHGs at all in order to set the surface temperature of the atmosphere.
Atmospheric pressure dictates the energy value of the latent heat of vaporisation so it is atmospheric pressure that dictates the rate at which energy can leave the oceans. The more it costs in terms of energy to achieve evaporation the warmer the oceans must become before equilibrium is reached.
So the oceans will build up to whatever temperature is permitted by atmospheric pressure with or without any non condensing GHGs in the air at all.
Once that ocean temperature is achieved the energy for the baseline temperature of the air above the surface is then supplied to the air by energy leaving the oceans and NOT by energy coming in from the sun and especially NOT by energy flowing down from above as so called back radiation.
So the upshot is that the oceans accumulate solar energy until they radiate 390 at current atmospheric pressure, at that point 170 continues to be added by solar but to balance the budget the atmosphere by virtue of its density retains whatever energy is required to achieve balance.
A feature of non condensing GHGs is that they add to the temperature of the air proportionately more than other gases in the atmosphere but in the end it is surface pressure that controls the energy value of the latent heat of vaporisation which is the ultimate arbiter of what rate of energy transfer can be achieved from oceans to air.
So if non condensing GHGs add a surplus over and above that required by surface pressure for equilibrium then the system has to make an adjustment but what it cannot do is alter the energy value of the latent heat of vaporisation in the absence of any change in atmospheric mass or pressure. So instead it is the rate of evaporation that must change to balance the budget in the absence of a significant change in surface pressure. Thus a change in the size or speed of the water cycle removes in latent form any excess energy produced as a result of non condensing GHGs.
There is no back radiation, merely a temperature for the atmosphere just above the surface and it is wholly pressure dependent. That temperature is a consequence not of downward atmospheric scattering of outgoing longwave but simply a consequence of atmospheric density slowing down energy loss first from sea to air and then by separate mechanisms from the air above the sea surface to space.
So if one increases atmospheric pressure at the surface the amount of energy required to provoke evaporation at the sea surface rises and the equilibrium temperature of the whole system rises including the temperature of the air above the surface.
The opposite if one decreases atmospheric pressure at the surface.
We have been looking at back radiation from the wrong point of view. There is no such thing. What we see is simply the air temperature near the surface and it is pressure dependent and not non condensing GHG dependent.
tallbloke, it may be allowed under his scheme, but he specifically rules it out as an explanation for earth’s climate change in the second sentence of his section 3.
“Climate change is not caused by changes in
atmospheric mass on Earth.”
With no GHGs the radiating level would be the surface and that temperature would need to be 255 K. This is not a small effect.
Jim, I suspect Jelbring has short term climate fluctuations in mind when he makes that statement. Hopefully he might clarify the position on my blog
http://tallbloke.wordpress.com/2012/01/01/hans-jelbring-the-greenhouse-effect-as-a-function-of-atmospheric-mass/
G. Karst says:
Really? Here are the links to my most substantive criticisms of this paper:
http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-846787
http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-846836
http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-847131
I await your links to where these criticisms has been “dismantled”.
Used: T = P/ ρ • M/R
Venus Earth Mars
——– ——– ——–
P – pressure 9220000 101325 605 N/m2 (Pa)
ρ – density 65 1.217 0.015 kg/m3
M – molar mass 0.0434 0.02897 0.04334 kg/mol
R – gas constant 8.31451 8.31451 8.31451 J/K/mol
——– ——– ——–
T – temperature 740.40 290.09 210.24 K
A couple of years ago I read a article stating that Earth had a rouglhy 10% denser atmosphere during the Permian Period than it does now , which helped make it warmer than it is now. From that article I thought I could apply the PV =nrT law to get the additional greenhouse effect from an Earth with a denser atmosphere, and Venus’s; surface temperature,. I quickly found a snag in my reasoning,
M, and R are determined constants, P is an input for an atmospher of a given density, but RHO is not determined by initial conditions,
If P is 10% larger and Rho is ALSO 10% larger, you get the same temperature as before.
Venus has a P of roughly 90. What determines Rho? If Rho was 130, Venus would have
a temperature of 370 K.
I suspect that Nikolov is messing around with an identity. .I don’t think his formula tells us how to calculate rho with a given atmospheric composition and density, and a given solar flux.
What would the surface temperature of a planet with a venus type atmosphere at 1/10 the Venus pressure, on a planet 10% more massive than earth, , at the distance of Mars, with a star having 90% the flux of our sun be? Once you have rho you can compute the other figures, and they will match the above calculations- but rho will depend on the stellar flux reaching the surface and on the geenhouse effect of the given atmpsphere.
Alan D McIntire:
Please explain the relevance to the Jelbring and Nikolov hyptheses of your post at January 2, 2012 at 8:41 am.
Richard
Alan, As I understand it, Nokilov and Zeller use the TOA insolation, not that at the surface.