Such potentially disruptive factors would include composition changes (not involving changes in atmospheric mass) on the surface or in the atmosphere. (newclimatemodel.com)
(Using a net total atmospheric mass of 4,900,000 Gt, this equals 55.0 % «remaining» in atmosphere. (judithcurry.com)
Could a flow of atmospheric mass between poles cause creation of different ozone concentrations, hence cloud cover, in different hemispheres? (judithcurry.com)