Problems. Gerlich and Tscheuschnur have problems.
Eli is adding this to the end of the paper. It is an abridged version of what Joerg Zimmermann wrote. A new (edited and less snarki? Eli has been informed that more desnarking is needed. He agrees (I don't, but what do I know) but he is quite willing for others to do the work, esp. since next week is conference time and his ears are in a twist. Ms Rabett is administering tender loving blows to the head to bring him down) version of the paper is available at Rabett Run Labs
The authors describe “problems” that are not really problems. They are either not related to the greenhouse effect, or well known and understood minor issues such as the differences between the mechanisms by which a glass greenhouse warms and that by which the greenhouse effect leads to a warmer surface. GT09 do not come to grips with how the greenhouse effect emerges at any significant level analysis typical of the modern state-of-the-art, such as from line by line calculations of atmospheric radiative transfer, global climate models (GCMs) or even on the level of advanced textbooks (Pierrehumbert 2009), but rather criticize simple, didactic models for not being complete. Their analysis of GCMs is limited to quoting from unrefereed sources and pronouncing on what they consider to be the requirements for a scientific theory. Further, they suggest that a good theory of radiative transfer would require use of inappropriate theoretical tools, such as Feynman diagrams for calculating vibrational emission and absorption probabilities in the atmosphere or magneto-hydrodynamics for analysis of flow in the lower atmosphere. In the first case quantum perturbation theory provides the theoretical background, and spectroscopic measurements the data base for line positions and cross-sections (HITRAN), in the second, discretized versions of the Navier Stokes equations for fluid flow in an unionized medium allow us to successfully model the major circulation patterns in the atmosphere.
GT09 begins with a three page discussion of thermal conductivity, showing that doubling the concentration of carbon dioxide would have a vanishingly small effect on heat transport by conduction, a point that no one disputes. Unfortunately they do not bother to quantify the role that conduction plays in atmospheric heat transport, which is very small, principally smoothing temperature profiles in the first meter or so of the surface-atmosphere boundary. Thermal conductivity k, is defined by dQ/dt = k A dT/dx where dQ is the heat transferred in time dt across distance dx and temperature difference dT. Since the thermal conductivity of air at 1 atm and 300 K is about 0.026 W/mK, the rate of heat transfer by conduction across 1 m and a temperature difference of 1 K would be 0.026 W/m2. In the atmosphere, the decrease of temperature with altitude, called the lapse rate, is ~10K/km. For atmospherically relevant distances the rate of heat transfer by conduction would be ~ 0.00026 W/m2 which compared to the hundreds of W/m2 transferred by convection and radiation can be ignored.
The citations are another problem. They include many books, including textbooks, without page numbers. One would have to read the entire book to discover where it supported or did not support a statement in the article. This is not helpful. Many of the cited books are works of opinion, not climate science. Many of the references are to polemics, anonymous contributions or newspaper articles. This is very unusual in a scientific article. Even many of the references to the scientific literature have no relation to the greenhouse effect or to questions of radiation balance.
Section 3.4 has a revealing example. It starts by quoting from a report by the U.S. Department of Energy, that the designation "greenhouse effect" is misleading, because greenhouses do not work the same way as the atmospheric effect does. This does not prove what GT09 assumes it does, that there is no clear definition of the greenhouse effect and that it would be impossible to experimentally observe the greenhouse effect. They extrapolate from this misreading to a general condemnation of climate science
For the fictitious atmospheric greenhouse effect one cannot watch anything, and only calculations are compared with one another. Formerly extremely simple calculations, they got more and more intransparent. (sic) Nowadays computer simulations are used which virtually no one can reproduce.143The reference is to the online Journal of Irreproducible Results, without any page or volume number. The authors provide no citations from the scientific literature for their extraordinary claims. The facts are that calculations of down and upwelling thermal IR radiation have been successfully compared with observations for the last fifty years. The many different radiative transfer codes have been incessantly compared with each other and measurements, leading to significant improvements over the years. (needs references) While it is true that with increasing complication interpretation becomes more difficult, that, after all being the point of simplification, increasing complication reveals more details, which again, is the point of increasing complication. One chooses the mixture sufficient for the educational or research purpose.
This type of citing is unfortunately typical of GT09. Where Gerlich and Tscheuschner do provide references, they often provide strained and incorrect interpretations. An outstanding example is found on pp 306, where they quote a description of the greenhouse effect by the German Meteorological Society (1995). In the second paragraph, the GMS writes,
Contrary to this, in the infrared range of the spectrum the radiation emitted form (sic) the ground is absorbed to a large extent by the atmosphere.. and depending on the temperature, re-radiated in all directions. Only in the so-called window ranges (in particular in the large atmospheric window (8-13 ?m) the infrared radiation can escape into space. The infrared radiation that is emitted downwards from the atmosphere (be so called back radiation) raises the energy supply of the Earth’s surface.Gerlich and Tscheuschner believe that the GMS statement means that
The assumption that if gases emit heat radiation then they will emit it only downwards, is rather obscure.The same occurs throughout Sections 3.3-3.4 where definitions of the greenhouse effect are discussed. Some of these are impossible to trace, as they are credited to “Anonymous” and not referenced. Others are to popular writings.
On page 309, they quote a definition from Rahmstorf’s web site. Rahmstorf’s explanation is ripped from its context in which he explains that the atmosphere emits longwave radiation which thereby contributes to surface heating in addition to solar radiation, thus warming the surface. The authors pretend that Rahmstorf had alleged that the greenhouse effect involves the reflection of radiation from the surface by the atmosphere. That is not what was written, and would of course be wrong. The authors then claim to have refuted Rahmstorf.
Gerlich and Tscheuschner claim in several places that others are confusing reflection with absorption followed by molecular emission, basing this on misreadings, as discussed above or illustrative figures taken from Al Gore's Powerpoint presentations. Section 3.5 is a four page discussion of the fact that absorption/emission is not reflection. Again, no one has ever claimed this to be true, only Gerlich and Tscheuschner claim that they have.
The authors introduce long lists of physical equations without any demonstration of where and why they are relevant. Many, indeed most of these can be neglected in climate models, such as those for conduction in the atmosphere. Section 4.2 is an example of this. In 4.2.2 to 4.2.10 GT09 derives a differential equation for the entropy density of a charged system starting from Maxwell’s equations, and conservation of mass and charge. They claim that magnetohydrodynamics is needed to treat atmospheric flows. There are very few ions in the troposphere and stratosphere, and they do not explain what is gained by introducing such a complication. In the last step they arbitrarily introduce a heat density source, Q, and a heat current density term, q, to represent the flow of thermal energy. They claim that these terms have no dependence on CO2 concentrations, but, of course, the equations that they wrote down do not include emission and absorption of radiation by molecules except by implication in Q and q. GT09 do not go beyond this single formula. They do not show how it could be applied to calculate global circulation or radiative transfer in the atmosphere. They do not discuss the methods used in state-of-the art radiative transfer or global climate models.
Based on this unsatisfactory exposition they close in Section 4.2 by attempting a philosophical statement about what a scientific theory should look like and, based on that, "prove" that according to their statements about climate models, the later are not scientific.
Here, we have merely touched on a few of myriad mistakes, misinterpretations and errors in GT09. It is difficult to understand how this paper was published