Let's examine whether this theory holds water, since there are no observations finding either the "hot spot" or an increase of the "effective radiating level" over the satellite era as predicted by the theory.
First, the theory summarized from slides from a climate science course at the University of Wisconsin:
And now multiple reasons why the theory does not hold water:
1. The effective radiating temperature of Earth is 255K or -18C, equal to the equilibrium temperature between the Earth and Sun, and the "effective radiating level" or "ERL" at this 255K temperature is located in the middle troposphere at about 5.5km above the surface:
2. The location of the ERL at ~5.5km in the tropics is part of the fabled mid-upper tropospheric "hot spot" region, which climate models predict will warm the fastest from AGW. Thus, an increase in height of the ERL would be offset by alleged warming from AGW in this same region of the atmosphere, countering the assumption that the increased height of the ERL would be colder and emit less radiation. Further, radiosonde observations show no evidence of the "hot spot" predicted by the models, and very slight warming of this region of the tropical troposphere since 1958:
3. Observations show no correlation between tropopause height and troposphere temperature 1980-2004:
|Open symbols show no relationship between tropopause height and troposphere temperatures|
4. Climate scientists assume the greenhouse gases CO2 and water vapor behave as true blackbodies and that the blackbody laws of Stefan-Boltzmann, Kirchhoff, and Planck can be applied to their radiative characteristics in the atmosphere. Measurements and a recent paper show this assumption is false, and that CO2 and water vapor emissivities behave the opposite of blackbodies, decreasing with temperature. The greenhouse effect models also make this same false assumption that CO2 and water vapor act as true blackbodies. Gases have distinct emission lines and do not follow a Planck curve of radiative emissions as all true blackbodies do.
5. Even if we assume CO2 does act as a blackbody and use the physical laws only applicable to blackbodies including Wien's Displacement Law, we find that at the peak emission line of CO2 at 15 microns, the equivalent blackbody temperature is -80C or 193K:
Therefore, the "blackbody" CO2 emits at a blackbody temperature of -80C or 193K, which is far colder than any portion of the troposphere, tropopause, or stratosphere as shown on the atmospheric temperature profile graph above. Changing the ERL does not change the "blackbody" emission temperature of CO2 one iota; CO2 emits at 15 microns/-80C no matter where it is located in the atmosphere. Thus, the notion that more CO2 can change the emissivity and emission temperature of CO2 is false and increases in ERL/CO2 levels cannot explain an increased greenhouse effect.
6. Even if an increased ERL could increase CO2 radiative forcing (already disproven above), it makes little difference to the troposphere since convection dominates over radiation in the troposphere and acts as a negative feedback that "short-circuits" radiative forcing from CO2.
7. Increased CO2 increases the radiative surface area of the atmosphere which increases the ability to radiatively cool, analogous to a bigger heat sink on your microprocessor. Warmists, however, don't agree on why increased CO2 allegedly cools the stratosphere but warms the troposphere.
|Modeling shows CO2 is the primary cooling agent of the stratosphere, and has a slight cooling effect on the troposphere as well|
Another model demonstrating that CO2 acts as a cooling agent throughout the entire troposphere and stratosphere, and as an alleged heating agent only at the tropopause near 15 km. and states,
“NOTE: CO2 has very small radiative heating rates. Radiation emitted at one level is absorbed at nearby level having almost the same temperature. Only at the tropopause (near 15 km), where the temperature profile has a minimum, there is a small amount of heating. At higher altitudes, pressure broadening is much weaker allowing emitted radiation to escape to space with little compensating radiation downward from higher levels.” Fig 12.1 also shows H2O acts as a cooling agent throughout the troposphere, tropopause, and stratosphere. [note these model results are also found in the lecture notes of Dr. Irina N. Sokolik, Climate Science Professor in Judy Curry’s Dept. at Georgia Tech]
8. The ERL theory predicts a decrease of outgoing longwave radiation [OLR] from increased greenhouse gases, however, observations show the opposite of an increase of OLR over the past 62 years.
9. The real 33C atmospheric greenhouse effect is instead entirely explainable on the basis of atmospheric mass/gravity/heat capacity/adiabatic lapse rate, and the "ocean greenhouse effect" explainable on the basis of the ~0.76 - 0.89 far-IR emissivity of the oceans, which "traps" heat from solar radiation in the oceans.