If the data were
perfect (which it isn't — look
at the spread in the different estimates of it), then you could make that kind of
calculation (but I have no idea what you are comparing here — what field?
In Kiehl and Trenberth 1997, they find a 155 W / m2 total greenhouse effect for approximately present - day Earth conditions (among the approximations: surface is a
perfect (isothermal **) blackbody, and the use a representative 1 - dimensional atmospheric column (instead of seperate
calculations for each location over the globe
at each time over the course of a period of time sufficient to describe a climatic state — but note righthand side of p. 200, just past halfway down the column)... a few other things).