This question is about the atmosphere. The AGW hypothesis as I have read says that the only way for heat to escape is via electromagnetic radiation into space. And it gives an account of the sun heating the earth's surface and then the earth releasing that into the atmosphere. Then this is blocked by greenhouse gases.
This is clearly not a technical account of the processes.
When the earth's surface is heated, the main cooling factor is actually convection into the air, everyone knows this from how a greenhouse actually works. A greenhouse blocks convection, and the glass insulates the inside from the outside. The CO2 content inside is actually to boost plant growth and has no significant effect on temperature. So the "Greenhouse effect" is obviously a simplification.
When the air heats up at the surface, does it not rise up into the atmosphere? As the gases rise, they lose Kinetic energy and gain Gravitational Potential Energy. Wouldn't this lower the temperature of that air?
Does the AGW take this into account, my basic understanding was formed from reading popular sites. I have no idea what goes into the technical discussions.
(If the whole earth rose in temperature, then the volume of the atmosphere would then increase, resulting in thinner air)