Yeaup… hard to believe. But all the stuff I’ve read so far of how the greenhouse effect works makes this same conflation that the entire effect of heating the atmosphere is due only to the infrared-absorbing elements of the atmosphere, i.e. the radiative heating part, ignoring the conduction & convection part.
The sun doesn’t heat the CO2 directly since the sun’s energy is mostly in the form of visible light, which the CO2 is also transparent to. See this link for example:
Q: Does the Sun ever heat the air, or does it only heat the land, which in turn heats the air?
Paul Harding: […] By the time the Sun’s radiation gets through the stratosphere, all the types of radiation which can heat air have been blocked and filtered out. What’s left is mostly visible light radiation, which zooms right through our part of the atmosphere - the mesosphere - without really interacting with it or heating it up at all. […] Those parts of Sunlight which make it down to us don’t heat the air down here, but they can heat surfaces which visible light doesn’t penetrate, such as the ground and even people.
This answer incidentally also ignores the effect of conduction and convection after said surface is heated:
The surface gets warmed enough to emit lower energy radiation of its own, and that wavelength of radiation can interact with certain substances in the mesosphere, such as water vapor, carbon dioxide, and methane, heating them up.
Presuming for now that you see the sun doesn’t heat the CO2 directly via IR, you would be saying that the surface is heating the CO2 directly via IR, which in turn heats the rest of the atmosphere. i.e. you are making the claim that the entire atmosphere is heated solely due to the CO2 (and other IR-absorbing gases) being heated by infrared (whether it’s from the sun or the surface).
Yet consider that:
1 - Out of conduction, convection, and radiative heating, radiative heating is the least efficient (as empirically demonstrated when designing cooling elements for space stations, see: Cause of Bias? - #196 by claudiu).
2 - The atmosphere is in direct contact with the surface of the Earth, which is hot, therefore it is getting heated by conduction and convection.
3 - 100% of the atmosphere is heated by conduction and convection, while only 0.04% of the atmosphere is heated by radiation.
So, which has the net larger effect of heating the atmosphere?
A - the 100% of it being heated by conduction and convection, the more efficient of the three heat transfer mechansims, or…
B - the 0.04% of it being heated by radiative heat transfer which then heats the rest of it.
This is very interesting. Is the “anticon” silver-backed insulation applies just on the underside of the roof space (i.e. the part facing the house) or also on the topside of it (I guess the part under the roof tiles??)
Also are there any other insulating properties of it, e.g. is it like a puffy not-dense air-filled sponge type of thing coated by a silver layer, or is it just a thin strip of silver?
Also is the issue with the ventilation that it doesn’t actually get ventilated well? e.g. it’s obvious that if the roof space were fully open to the room it would just be the same temperature of the room, due to convection. So perhaps the ventilation isn’t enough due to the physical barrier blocking the convection in the first place, i.e. it’s not enough to reach the same level of convection that would be if there were no barrier betwixt the two.
BTW you get the prize for the first reply actually addressing the argument 
. Congrats and I appreciate it, it makes for a fun discussion.