This is going to deserve more study

I invite comments on this, and I'm going to append several posts as I see comments developing. Here's the preliminary salvo:

Cosmic ray decreases affect atmospheric aerosols and clouds

"A link between the Sun, cosmic rays, aerosols, and liquid-water clouds appears to exist on a global scale," the report concludes. This research, to which Torsten Bondo and Jacob Svensmark contributed, validates 13 years of discoveries that point to a key role for cosmic rays in climate change. In particular, it connects observable variations in the world's cloudiness to laboratory experiments in Copenhagen showing how cosmic rays help to make the all-important aerosols."

Well let's see where this goes, shall we?