( Boy I wish there were a way to preview posts . ) Wayne , your question @ May 16, 2010 , 05:27 highlights why I continue to judge the quality of understanding of the basic physics apparent on both sides of the conflict is pathetic . Certainly , so called "climate science" has become detached from the fundamental quantitative constraints well understood a 100 years ago .

I keep being given lists of $100 textbooks to slog thru to understand the problem . But if any of them had the definitive quantitative , ie , equation by equation , experimentally confirmed , explication of planet/atmosphere temperature profile , we would not be having this controversy . There certainly has been no Chandrasekhar in the field and that strikes me as bizarre given that these issues appear much simpler than those he analyzed .

 I'll be so bold as to assert that my own implementation , in several modern Array Programming Languages , of the StefanBoltzmann & Kirchhoff relationships for non-uniform gray ( flat spectrum ) spheres with arbitrary surrounding heat sources and sinks is the clearest and most general explication of the first-cut calculations which explain all but about 3% ( 9 kelvin ) of our temperature .

I'll attempt to insert here the graph of the "Calculated & Observed Temperatures of Inner Planets" which I thank Dr Bill for his complement about the other day . Calculated & Observed Temperatures of Inner PlanetsIf it didn't show , you can find it on my website .

You will see how enormously higher the surface temperature of Venus is compared to a gray ball in its orbit simply heated by the sun . Given the StrfanBoltzmann P = sb * T ^ 4 relationship , where the sb constant drops out of any comparisons of temperatures between bodies , the surface of Venus is trying to radiate more than 16 times the amount of power it is receiving from the sun .

Sorry dr.bill , Wayne 's right on his intuition that "black" and "white" balls will come to the same temperature . That was Kirchhoff's incredible insight 151 years ago . But it applies to flat spectra so that the correlation between the ball's spectrum and its heat sources and sinks will be the same . That's why the graybody temperature is the first term to be extracted . It is orthogonal to spectrum , thus makes no difference whether dark or light . I have never found a quantitative definition of "the greenhouse effect" on the web -- which is all that matters . So I'll give one which makes sense :
GHE is the ratio of the correlations between the spectra of an object and its radiant sources and sinks
since this is the ratio between absorptivity from sources versus emissivity  towards sinks . Given any set of object and source and sink spectra , the equilibrium temperature can be calculated .

I'll leave as a homework assignment for those who understand vector geometry what spectrum of an object will maximize its temperature for a simple situation like our sun's spectrum versus the 3k cosmic background .

If the mean surface temperature of a planet exceeds that value , then it must have an internal source of heat .

Since I don't have the time , you will find on my website that I am offering $300 to any student who elaborates the handful of lines of my algorithms to calculate values for full spectra - and calculates the equilibrium temperature for a bunch of spectra of interest such as pure CO2 . That's well below minimum wage but the answers should be most interesting .