Time for water vapor to generate more greenhouse effect than latent heat?
I am doing some calculations on this question myself. The atmospheric lapse rate is about 6.5K/1.000m. The adiabatic lapse rate is 9.8K/1.000 and the dry lapse rate of the naturally unstable atmosphere of Earth should even be 10.8K. So arguably the constant transport of latent heat by vapor from the surface into the atmosphere is reducing the lapse rate by some 4.3K/1.000m. Without a doubt the GHE would be much larger if it was not for the latent heat provided by vapor.
The GHE itself is a function of the emission temperature, which again is a function of the emission altitude. Vapor increases this emission altitude, which is why it is considered a GHG, the most significant one actually.
We need to ask what size GHE has (not 33K, but less), what bigger size it counterfactually had without latent heat and a lapse rate of 10.8K, determine the share of vapor in this case, and compare it to the (negative) effect of latent heat. Depending on what is bigger, vapor is either a GHG or an anti-GHG. From all the modelling so far I get definitely the latter result.