What is a Watt???

[Richard111]

Yes, volts times amps equals power in watts but this is an instantaneous value only valid at the time the measurement is recorded.

This argument applies to the Boltzmann method of calculating IR radiation. The watts per metre squared rate of power loss is indeed that number of joules FOR JUST ONE SECOND. There are a huge number of variables in the heat capacity and mass, and conductivity etc that effect the final figure as time passes. i.e. at night the surface is continually cooling until the sun comes up whence it starts warming until the sun goes down. The intensity of these effects also change with the seasons which respond to the altitude of the sun.

This does not mean the W/m^2 figure is wrong, just that it is usually misapplied.

I think we need to go read up on a chap named Fourier (spelling) as his argument includes radiation AND conduction between surface and atmosphere to calculate heat transfer.

The Boltzmann method is for bodies in VACUUM! That is where I think "they" are going wrong.