The above diagram is supposed to capture the essence of the science of CO2 global warming alarmism. We see massive "Back Radiation" of 324 W/m2 hitting the Earth's surface from the "Greenhouse Gases" below the Top of Atmosphere TOA, while the net radiative transfer from the surface to TOA is 26 W/m2, about 10 times as small.
The main "greenhouse gas" is water vapor with CO2 contributing maybe 10% to the total "greenhouse effect" of 33 C as the difference between the surface temperature and that of TOA.
To estimate the effect of a doubling of CO2, one can argue as follows: The total "back radiation" from "greenhouse gases" is about 300 W/m2 and so the total effect of CO2 can be estimated to 30 W/m2, which according to Stefan-Boltzmann may correspond to a global warming of 7 C, which is the upper limit of CO2 alarmism, without taking any saturation reduction effect into account.
On the other hand, using instead of a nominal 300 W/m2, a net of 30 W/m2, we end up with 0.7 C as the upper limit, without saturation effect.
We thus have the following two estimates for global warming upon doubled CO2 to compare:
- With "back radiation": 7 C
- Without "back radiation": 0.7 C
Here 1. is catastrophical, while 2. is harmless.
We see the critical role of "back radiation" for CO2 alarmism.
But "back radiation" is fiction without physical reality, and so is then also CO2 alarmism.
Of all scientific bluffs through the history of science, "back radiation" will be described as the biggest, as the bluff with potentially biggest effects for human civilization.
For a deeper analysis of "back radiation" see earlier posts in categories "radiative heat transfer" and "myth of back radiation".
In my opinion, the “energy” budget is fundamentally wrong. It is not an “energy” (given in the energy unit Joule) budget at all, but a radiation calculation given in Joules per second and square meters ( J/(sm^2) = W/m^2).
SvaraRaderaFirst and foremost; the total solar irradiation (TSI) on the top of the atmosphere (TOA) ca 1368 W/m2 shall not be evened out over the whole earth in the second this radiation is calculated, but only over half of the earth. It is thus wrong to divide 1368 W/m2 by 4, instead the TSI shall be divided by 2. Thus the radiation reaching the earth surface in 1 second is twice that given in the figure; 236 W/m2 instread. Outgoing radiation, however, takes place over the whole earth and has been measured to totally ca. 242 W/m2. Calculating in this way eliminates the need for a “back radiation” loop increasing the temperature by +33 Kelvin. Besides in a radiation calculation the sum in minus out does not need to be 0, because some energy can be stored and released later (e.g. coal and petroleum).
For a real energy budget it is necessary to integrate radiation over time and earth area. Some climate science scrutinizers have done this, e.g. Joseph Postma, see http://principia-scientific.org/publications/Absence_Measureable_Greenhouse_Effect.pdf . Postma has shown that his calculation explains the temperature on the earth without “back radiation”.
Claes, your opinion on this is highly appreciated.
The atmospheric window is actually 66 W/m2 as admitted in an email by Dr Trenberth to Dr Noor van Andel. If you add the evaporation (78 which may low) and the convective heat (24 which also may be low) the total is 168 W/m2 which is the same as that supposedly absorbed by the surface. Hence there is no additional surface radiation which could be absorbed by the atmosphere. In my experience with heat loss from surfaces, eg furnace walls, pipes and ducts etc, to surroundings and the atmosphere convection always exceeds radiation. Also from hundreds of process heat balances, the heat loss to surroundings has always been less than calculated from measured surface temperatures (radiation & convection) and air movement ( convection). Basically, the Stefan-Boltzmann relation does not work because there is no vacuum. As Baron Fourier wrote in a treatise when there is an atmosphere everything changes (or words to that effect).
SvaraRaderaYou are right there is no backradiation and it can and has been proven.