A human body with surface 1 m2 sitting still in a room without air circulation and windows eating a standard ransom of 2.000 kcal/day produces a heat power of 80 Watts (two standard light bulbs), which has to be transferred by radiation to the room walls (no convection/conduction) to keep stationary state and not overheat or freeze.
Assuming a body surface temperature of 30 C and a wall temperature of 10 C, we can compare with Stefan-Boltzmann's Law stating a radiative flux from body to wall of about 80 Watts/m2 upon a temperature difference of 20 C. This is basic physics. If the wall temperature was 20 C then the heat transfer would be 40 Watts/m2 and so the body would overheat. If the wall temperature is 0 C, then you will freeze to death unless you increase your intake to 3000 kcal/day. This may be the case for the coming Winter.
We are here clearly speaking about one-way heat transport from body to wall. Let us now compare with the center piece of CO2 alarmism, which is two-way heat transfer between a colder atmosphere and a warmer Earth surface with "back radiation" from the atmosphere to the Earth surface of size 350 Watts/m2 to be compared with the around 200 Watts/m2 absorbed from the Sun.
This can be compared with the human-room situation in the case of a temperature difference of 10 C corresponding to a net heat transfer of 40 Watts/m2 and would then postulate a radiative heat transfer from wall to body of 350 Watts/m2, to be balanced by outgoing radiation from the body to wall of 390 Watts/m2 with a net of 40 Watts/m2. The two-way heat transfer of CO2 alarmism thus postulates a massive back-and-forth heat energy transfer between body and wall of size 400 Watts/m2 (the power of two Suns) while the net is small 40 Watts/m2.
Your body is thus supposed to be shining like two Suns which is balanced by the walls also shining like two Suns. Shining like two Suns could boost your ego, but you understand that this can only be fiction, right? If so, then you also understand that the back radiation of CO2 alarmism is also fiction.
Why is massive back-and-forth heat transfer between bodies unphysical? Because it is unstable and as such not physically sustainable over time. Only net heat transfer from warm to cold is stable and thus physically possible and then in fact also real. See Computational Black Body Radiation.
The unphysical nature of back radiation can be seen in the functioning of a pyrgeometer discussed in previous posts clarifying that a pyrgeometer de facto measures a temperature difference and in no way gross back radiation, which is a derived ghost quantity which cannot be directly measured because it lacks stable physical realisation. Similarly your body can register the temperature of the wall of the room you are sitting in, but has no collector counting photon particles spitted out from the colder wall, nor any sensor counting photons emitted by your body.
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BTW, Claes, you can feel free to use anything I write in any way you wish, with or (preferably) without attribution. Change it, rewrite it to make it clearer, use it as-is, whatever.
SvaraRaderaThe images coming from imgur.com are my own creation or adaptations of images taken from elsewhere (in which case, they will have attribution within the image or (where including attribution in the image isn't possible) directly below the image).
The S-B animated GIF is my own creation. You're free to use my images however you wish, with or (preferably) without attribution.
I'm not looking for fame, glory, money or recognition... I want to destroy CAGW before it and its Marxist One World Government "Build Back Better" companion destroy our civilization.
Fine, thanks!
SvaraRaderaThe climastrologists misuse the S-B equation, using the form meant for idealized blackbody objects (q = σ T^4) upon graybody objects, and slapping ε onto that (sometimes) (q = ε σ T^4), which by looking at the S-B equation:
SvaraRaderahttps://i.imgur.com/QErszYW.gif
... means they're presuming all graybody objects emit to 0 K, which inflates radiant exitance for all objects, necessitating that they carry those incorrect values through their calculation and cancel them on the back end, essentially subtracting a wholly-fictive 'cooler to warmer' energy flow from the real (but too high in magnitude because it was calculated for emission to 0 K) 'warmer to cooler' energy flow.
The S-B equation for graybody objects isn’t meant to be used to subtract a fictive ‘cooler to warmer’ energy flow from the incorrectly-calculated and thus too high ‘warmer to cooler’ energy flow, it’s meant to be used to subtract cooler object energy density (temperature is a measure of energy density, the fourth root of energy density divided by Stefan’s constant) from warmer object energy density. Radiant exitance of the warmer object is predicated upon the energy density gradient.
In effect, the climastrologists isolate each graybody object into its own system, unable to interact via the EM field with other objects and emitting to 0 K, then through hand-wavium, they 'connect' the two objects by canceling the cooler object's fake 'cooler to warmer' energy flow from the real (but too high in magnitude because it was calculated for emission to 0 K) warmer object's 'warmer to cooler' energy flow.
That's not how reality works, that's not how objects interact in the real world.
We can use a real-world example to demonstrate this point.
There exists custom materials which have a high reflectivity in the visible wavelength range, and a high emissivity in the 8 - 13 µm wavelength range... used to enhance passive cooling.
Now why would they do that, if they didn't know that it is the energy density gradient which determines warmer object radiant exitance?
What's taking place with these materials is that they reflect a very high proportion of visible range solar insolation, and emit primarily in the 8-13 µm range... which just so happens to be in the Infrared Atmospheric Window.
So what they're really doing is preventing the material from heating up from absorbing visible range wavelengths... but the important part here is the high emissivity in the 8-13 µm range.
That allows radiation in that range to 'see' the coldness of space through the Infrared Atmospheric Window, which increases energy density gradient between heat source (the material) and heat sink (space), rather than 'seeing' the comparatively much-warmer atmosphere by emitting at other wavelengths. Thus radiant exitance in the 8-13 µm range is higher than if the material were emitting at wavelengths outside the Infrared Atmospheric Window (which would 'see' a higher temperature and thus have a lower energy density gradient).
Anodized 1150-grade aluminum (anodized for >= 180 seconds in 10% sulfuric acid using 13 VDC current and an aluminum concentration of 5 - 15 g l-1) coated with 1mm of ZnS makes an excellent selective radiator for this purpose. It is a tough material, standing up to UV radiation just fine, whereas the polyethylene selective radiator materials in common use now break down over time from UV exposure.