I looked it up again, and it seems like we're both a bit correct.
My explanation would be correct if the earth is in equilibrium and there is no primordial heat left and all heat comes from radioactive decay, but surprisingly (to me at least) that is not the case. About 1/2 of the heat flow from the core to the surface comes from primordial heat.
I'd say solar will also add some heat to the atmosphere because they reflect less sunlight than the surface.
Of course, in the big scheme of things this is all pretty irrelevant unless we keep on exponentially increase our energy usage. The greenhouse effect of CO2 is a few orders of magnitude higher.
My explanation would be correct if the earth is in equilibrium and there is no primordial heat left and all heat comes from radioactive decay, but surprisingly (to me at least) that is not the case. About 1/2 of the heat flow from the core to the surface comes from primordial heat.
I'd say solar will also add some heat to the atmosphere because they reflect less sunlight than the surface.
Of course, in the big scheme of things this is all pretty irrelevant unless we keep on exponentially increase our energy usage. The greenhouse effect of CO2 is a few orders of magnitude higher.