Anyone who <i>thinks</i> about these points will realise there is no greenhouse effect ...
<b>(1) The direction of net radiative energy flow can be the opposite of the direction of heat transfer.</b> if you have a warmer object (say 310 K) with low emissivity (say 0.2) and a cooler object (say 300 K) with much higher emissivity (say 0.9) then net radiative energy flow is from the cooler to the warmer object. Yet the Second Law says heat transfer is from hot to cold. So, there is no warming of the warmer body by any of the (net) radiative energy going into it.
<b>(2) Any warming of a warmer surface by radiation from a cooler atmosphere violates the Second Law of Thermodynamics.</B> Consider the situation when the surface is being warmed by the Sun at 11am somewhere. Its temperature is rising and net radiative energy flow is into the surface. How could additional thermal energy transfer from the cooler atmosphere to make the surface warm at a faster rate?
Clearly radiation from a cooler atmosphere cannot add thermal energy to a warmer surface. The surface molecules "reject" radiation which has a peak frequency lower than the peak frequency of their own emission, and so no radiative energy is converted to thermal energy. (This was proved in Johnson's <i>Computational Blackbody Radiation.</i>), So <b>the atmospheric radiative greenhouse effect is a physical impossibility.</b>
↧