Evidence of Zero Greenhouse Gas Effect 2

By universality of blackbody radiation the temperature of a planet orbiting the Sun, both assumed to be ideal blackbodies, would only depend on the distance to the Sun and not on the composition of the planet including its atmosphere. We would then expect the blackbody temperature to be the "surface" temperature of the planet including its atmosphere as the temperature of the "outermost layer" of the atmosphere, which would also be the smallest temperature assumed.

Data like that above suggests that this layer is defined by an atmospheric pressure of 200-400 millibar, which for a gaseous planet like Jupiter defines an "effective outer boundary" as a radiating body.

The solid surface temperature of planet, like the Earth or Venus, would then be determined by a lapse rate set by thermodynamics, and would thus be independent of the radiative properties of the atmosphere including the concentration of CO2, thus contradicting the presence of any greenhouse gas effect, on both the Earth and Venus.

See also No Greenhouse Effect with the observation that the temperature of Venus is about 1.176 times that of the Earth at the same pressure level, which conforms with the difference of blackbody temperatures from different distances to the Sun.

PS The albedo would then be taken into account by reducing the effective blackbody temperature at a certain distance from the Sun, alternatively effectively increasing the distance to the Sun. For example, with albedo = 0, the effective Earth blackbody temperature would be 273 K, and with the observed  albedo = 0.4, it would be 240 K attained at a pressure of about 300 millibar.