Is there anything in the independent physicist Harry Dale Huffman's suggestion in the comments to the 'A new survey' post on 11 August at 6.20 that comparing conditions on Earth with those on Venus (or another planet) could tell us a great deal about the influences on temperatures here and the influence of the Sun.

He says that his comparison of Venus/Earth temperatures "showed that the Venus/Earth temperature ratio is a constant that is precisely explained by the ratio of the two planets' distances from the Sun and nothing else (so there is no global warming "greenhouse effect", due to increasing CO2, at all)."

Is there any published work in this area? Not that I would be able to understand it – I'm not a physicist – but it seems like a good way to assess the impact of the Sun. No?

If he was using Venus surface-atmospheric temperatures, then that would be valid. Unfortunately since the Venera project of the late 70s and early 80s, we don't have any ground or lower atmosphere based temperature measurements to compare with.

Remember, because the TOA of Venus is in thermal equilibrium, it's temperature is known and can be calculated simply as a function of its solar insolation. Likewise the temperature of the earth's TOA is well known and can be calculated as a function of its solar insolation. There is no surprise that both TOA measurements would be in
lockstep, since both are driven solely by solar insolation.

For his comparison to work, you would need to compare the ratio of lower or ground atmospheric temperatures,
and since we're not measuring this for Venus, I think this knocks it on the head.

Thanks TBYJ. I didn't understand much, but managed to grasp that there isn't really any data.

My badly explained point was that when we measure the temperature of a far planet such as Venus, we are actually measuring the temperature of the Top of the Atmosphere (TOA).

The TOA is emitting energy (at a temperature) at the same level as it receives it from the sun (in thermal equilibrium), and we can calculate what portion of sunlight each planet receives from the sun (by geometry), and thus calculate what 'temperature' a planet's TOA is. None of this is affected by GHG.

This doesn't really help us with what the temperature at ground level is, since this is the part where GHG do have an effect. The TOA is always at a temperature driven by the sun, the ground level atmosphere isn't, it's influenced by other factors such as GHGs.

Since Venus doesn't have man-made increases in CO2, we can assume it has been fairly static for the last century or so. If we could compare the ratio of earth ground-level temps, with Venus ground-level temps, you could conceivably pick out the existence (or not) of the man-made influence. Maybe. Maybe.

But... since we have no ground-level Venus measurements.....the game's a bogey, as we used to say.

Thinking about it, if you compared earth ground-level temps with Venus TOA temps, and found the ratio was almost the same, it would be an indicator (not proof) that the warming we have seen was natural, since it was also duplicated on Venus.

Isn't this the same thing as seeing if earth ground level temps correspond with solar output? Why bother going via Venus?

So half a hat to him.

Thanks for the clarification in simpleton's terms, TBYJ.

Richard, I'm not sure what your point is.