Commenter ‘Paul’ on Dr Roy Spencer’s blog writes:
John Nicol, PhD, Professor Emeritus of Physics, James Cook University, Australia, states in his paper Climate Change (A Fundamental Analysis of the Greenhouse Effect),
http://www.middlebury.net/nicol-08.doc
The 22 pages of closely argued, mathematical and physical analysis of how energy is transmitted from the surface through the atmosphere, answers all questions and demonstrates that : –
1) Water vapour and clouds dominate the troposphere’s ability to absorb outgoing long-wave radiation, with the amount of water vapour decreasing with altitude. Most absorption occurs in the first few meters of atmosphere above the surface.
2) 99% of the absorbed photons are not re-emitted, due to collisions with other molecules and the consequent sharing of the energy, effectively converting all LWR into kinetic energy is a very short space and time.
3) Convection is the predominant method of transferring heat through the troposphere.
4) Radiation transmits the energy above the troposphere, with ever widening radiation windows with altitude.
5) The back-radiation from the atmosphere to the surface is both fixed and minimal for any level of atmospheric CO2 and other photon-absorbing gases.