Re: Energy and global warming
Reply to Paul Ward
Many thanks again for helping to get my ideas sorted out.
The anthropogenic energy, after use by mankind, enters the Earth?s atmospheric system as heat, ie. as increased kinetic energy of the air molecules. This, of course, does not cause internal molecular excitation, and so no radiation can occur, even from the GHG components. Since the Earth is isolated in space, no energy can escape into space by conduction or convection, and so the anthropogenic energy is retained within the Earth?s system, and builds up over time and so causes global warming. (See below).
This extra energy in the atmosphere is circulated by the normal currents towards the poles in the usual way, where it causes extra ice to melt, as calculated. Naturally, some ice reforms during the winter, so releasing its latent heat into the system again, but a greater amount is melted during the following summer because the latent heat just liberated is still available in the system and yet more anthropogenic energy has also been injected during the intervening months.
If no energy entered the actual surface of the Earth, land or sea, after leaving the polar region in the Northern hemisphere in the usual way, there would be sufficient remaining energy to raise the temperature of the atmosphere in the Northern hemisphere by 1.8 degC. However, let us assume that enough energy enters the surface to make the actual temperature rise of the atmosphere only 0.6 degC, in line with the practical observation over the last 150 years. Then the amount that enters the surface can indeed be radiated away (apart from the effect of the ?pre-industrial? GHG effect), but the increase in temperature of the surface required to achieve this is less than 0.1 degC owing to the fourth power temperature dependency of the Stefan-Boltzmann law. Such a small rise would be virtually impossible to detect with present techniques.
The factor of 2 figure I gave for melting of the ice comes from the latest energy information I could find and applies to 2003. This amount can melt over 1300 Gt of ice in one year, whereas the best practical figure I have is less than 600 Gt, where 1 Gt is 1 thousand million metric tons, which leaves a lot of energy over to warm the atmosphere.
However, the comparison I made in my paper for the Arctic sea ice was for a 25 year period from 1978 to 2003, for which energy production data was available and for which practical observations happened to have been made.
Aubrey E Banner, Sale, Cheshire, UK