(A) is false - while water vapour has high radiative forcing, it is not "an important greenhouse gas" in the big picture, unlike what the coal industry reps say. This [1] should explain why. Methane and CFCs are far less important in aggregate (about 1/3 and 1/4 of the effect of CO2 respectively), although they are far more dangerous per unit of volume.
(C) is obviously false - even in the low level layman explanation in [1] you can see that they include a table with the forcings of various combinations (like H2O vapour+CO2); you can also see that the table is from 1978, so scientists have done that since way before you were born.
Thanks for your thoughtful reply and your link. I think that article is quite informative, and also well written. I guess it was not authored by the coal industry, but still it states literally "water vapor is indeed the most important greenhouse gas".
(A) is false - while water vapour has high radiative forcing, it is not "an important greenhouse gas" in the big picture, unlike what the coal industry reps say. This [1] should explain why. Methane and CFCs are far less important in aggregate (about 1/3 and 1/4 of the effect of CO2 respectively), although they are far more dangerous per unit of volume.
(C) is obviously false - even in the low level layman explanation in [1] you can see that they include a table with the forcings of various combinations (like H2O vapour+CO2); you can also see that the table is from 1978, so scientists have done that since way before you were born.
(D) false
[1] http://www.realclimate.org/index.php/archives/2005/04/water-...