FC, I have read that 2010 Lacis paper from Nasa.
Here is a another quote from it: "carbon dioxide itself is a potent greenhouse gas (GHG) warming the ground surface by means of the greenhouse effect. It is this sustained warming that enables water vapor and clouds to maintain their atmospheric distributions as the so-called feedback effects that amplify the initial warming provided by the non-condensing GHGs, and in the process, account for the bulk of the total terrestrial greenhouse effect.
(underlining is mine.) He is referring to Water here as accounting for the bulk of the "total terrestrial greenhouse effect."
You have read the Lacis statement you quoted, as you wanted to, ignoring all the while its true message. Specifically, you ignored this part of your own quote: "... the non-condensing greenhouse gases account for only 25% of the total greenhouse effect..." This is Lacis saying this! Not me!
Are far as I can tell, based on our current knowledge, it is simply wrong to go around saying CO2 is the dominate greenhouse gas. It isn't! What Lacis has said very clearly is that CO2 is a critical component in the overall temperature control mechanism and that it works in conjunction with water. But he has also made it clear, as have I, that water is the dominate greenhouse gas.
I'll summarize my opinion once more for you:
"I believe the critical error that the early investigators made, besides letting the issue be turned into a political football and becoming emotionally involved, was to look at CO2 on too short a time scale and not pay enough attention to changes in incident radiative flux plus thermal flux from the earth's core. They treated CO2, or at least the popular press did, as you would if it were the energy source, but of course it is not. This led to incorrect statements such as "CO2's main effect is to increase temperatures," when clearly that is only an incidental effect under specific conditions.
It is not incorrect to say: "CO2's effect is to increase temperatures," but such a statement can be too easily misinterpreted by non-scientists. Why? Because it is easy to jump to the conclusion that if CO2 goes up the temperature must go up as well. But we scientists know that is NOT true. CO2 can go up and temperature can go down, just not as much down as it would if there was not as much CO2! Furthermore such a simple minded statement doesn't mention any of CO2's other critically important effects! If you, however, insert the word "main" into that statement above, then the statement is incorrect! CO2 has more than one very important "effect"!!!
These silly arguments here on ET are what happens when a very complex mechanism gets distilled down into sound bites, as one might hear on CNN or read in USA today.
It is far better to put it this way; "One of CO2's effects, among several important other effects, is to help moderate temperature, in conjunction with water, by altering the rate of heat dissipation from the Earths surface."
It seems what I have written in this post more or less summarizes the entire problem with the current misunderstanding of CO2's role promulgated by the media and non-science climate enthusiasts.