This is in reference to a discussion at:
Tallbloke’s blog by Stephen Wilde. My response is something of a tome so I am going to post it here. I don’t do this stuff for a living so take this in the spirit of me possibly talking through my pants a bit. The approach is one from first principles and from some additional reading on the subject. So, here we go:
i) The stratosphere and the mesosphere actually cooled when the sun was more active and are now warming now that the sun is less active. There must be something else going on to account for that.
Yes, there could well be other things involved. But, an increase in UV should increase excitation in the stratosphere and increase temperature from where it would be without it. There may be other things going on that influence that however, and swamp that. In other words, the stratosphere cooled while the sun was active, yes, but maybe it was still warmer than it would have been and might have cooled even MORE if the sun were not so active.