this whole discussion about the various temperatures and cooling or warming rates of the upper and lower layers of the atmosphere seems to me totally pointless in view of what I said earlier i.e. it is the factors that
govern cloud formation & overcast conditions that drive global temperatures.
The suggested hypothesis, is that in regions devoid of dust (e.g., over the large ocean basins), the
formation of
cloud condensation nuclei takes place from the growth of small aerosol clusters, and that the
formation of the latter is
governed by the availability of charge, such that charged aerosol clusters are more stable and can grow while neutral clusters can more easily break apart.