So he completely ignores radiation and then calculates how heat is transferred in the system. Okay. Yeah so convection, evaporation, and condensation do the lion's share of the work of moving heat around in the atmosphere and exchanging heat between the atmosphere and the land. That's no new contribution to knowledge.
Umm. The air that rises to then expand and cool rises because it is warmed by radiation or by latent heat from ocean water that was warmed by radiation. The less transparent the air is to radiation, the more it is warmed by radiation. If you ignore radiation and model a system without radiation you can make the numbers work but you aren't describing the system as it is.
Maybe the writing is sloppy? The blog post linked makes it seem like he has modeled how the atmosphere would behave if it closed with respect to heat and there's no radiation of heat out to space.
Feynman begins to explain in the 7th paragraph and for the remainder of the entire paper why our atmosphere (and he only assumes the atmosphere is comprised of non-greenhouse gases N2 & O2) “is not an isothermal atmosphere” due to the thermodynamic work done by gravity upon all gases.
Well thanks for pointing that out. People never noticed that before while studying frontal systems or tropical cyclones. What's the next huge revelation, the oceans aren't isothermal because of convection and gyres? Gee golly. Was buoyancy driven convection a novel concept to him when he started thinking about this?
I'm wondering, how does his model explain the increase in total heat in the system that we have observed over the last 100 years in the form of higher average temperature and higher water vapor content in the air?