13 years ago, amateur scientist Willis Eschenbach developed a thought experiment that he hoped would very simply illustrate how the Greenhouse Effect works.
The main claim is that the addition of a steel shell surrounding a planetary surface will cause the inner surface to emit TWICE (235 -> 470 W/m2) the radiation as compared to not having steel shell. This should significantly raise the surface temperature from ~254K to ~302K.
Is this true? No.
Willis gives us the freedom to construct any power source with any chosen radius. I will choose a mini nuclear reactor wrapped in a steel housing, with the total surface area being 1 m2. The inner radius of steel housing is 75% of total radius.
Let us go through the equations to make set up Willis’ initial scenario (A):
The nuclear power reactor is ONLY capable of making its wall 254.041K – to meet Willis’ initial criteria. It is not capable of anything greater, because nuclear reactions are fixed. No varying levels of downstream radiation will enable nuclear fission reactions to generate more joules.
Now let us see what happens when we add a steel shell (B):
I will give Willis credit for doing a good job of demonstrating the real greenhouse effect:
Outgoing radiation is halfed and T2 (our “surface”) has increased from 253.726K to 253.884K, a very feeble gain.
The problem with Willis’ approach is that he doesn’t reduce outgoing radiation and relies on his heat source to crank up … when there is no physical way it can do so.
|T#||Willis A||Willis B||Reality A||Reality B|
|T2||253.726K (235W)||301.732K (470W)||253.726K (235W)||253.884K (235.588 W)|
|T3||253.726K (235W)||213.490K (117.393 W)|
So there you have it. The real steel greenhouse effect managed to raise the surface temperature by 0.062%.
Subsequent additions of steel shells will keep raising the surface temperature (T2), in an inverse asymptotic fashion approaching nuclear reactor wall temperature (T1).
Enjoy 🙂 -Zoe