Best Answer:
Surprisingly to most, there is no greenhouse effect at all, and you can prove it for yourself. You can find the temperature and pressure profiles for the Venusian atmosphere at

http://www.datasync.com/~rsf1/vel/1918vpt.htm

With those graphs, you can confirm that, at the altitude where the pressure = 1000 millibars, which is the sea level pressure of Earth, the temperature of the Venusian atmosphere is 66ºC = 339K.

This is much warmer than the temperature at the surface of the Earth, at pressure = 1000 millibars, which is about 15ºC = 288K. HOWEVER

Venus is closer to the Sun, and gets proportionally more power from it. Earth is 93 million miles from the Sun, on average, while Venus is only 67.25 million (on average) from the Sun. Since the intensity of the Sun's radiation decreases with distance from it as 1 over r-squared, Venus receives (93/67.25) squared, or 1.91 times the power per unit area that Earth receives, on average.

Since the radiating temperature of an isolated body in space varies as the fourth-root of the power incident upon it, by the Stefan-Boltzmann law, the radiating temperature of Venus should be the fourth-root of 1.91 = 1.18 times that of the Earth. Furthermore, since the atmospheric pressure varies as the temperature, the temperature at any given pressure level in the Venusian atmosphere should be 1.18 times the temperature at that same pressure level in the Earth atmosphere, INDEPENDENT OF ANY INFRARED ABSORPTION in the atmosphere. In particular, the averaged temperature at 1000 millibars on Earth is about 15ºC = 288K, so the corresponding temperature on Venus, WITHOUT ANY GREENHOUSE EFFECT, should be 1.18 times that, or 339K. But this is just 66ºC, the temperature we actually find there from the temperature and pressure profiles for Venus.

So there is no greenhouse effect. You have just proved that climate science is utterly wrong to think otherwise. This is the scandal that so many "experts" in climate science, and all the scientific authorities, will not face. Listen to the physicists that tell you there is no greenhouse effect; they know without having to go to the Venus data -- and I am one of them. The continuing incompetence on this vital point among so many scientists, for more than a century, is amazing, and tragic..

Source(s):
http://www.datasync.com/~rsf1/vel/1918vpt.htm