"Global cloudiness" refers to the measurement or extent of clouds covering the entire Earth's atmosphere. It describes how much of the sky is covered by clouds on a global scale. Full definition
The changes in both satellite derived and measured surface insolation data are also in line with changes in global cloudiness provided by the International Satellite Cloud Climatology Project (ISCCP), which show an increase until the late 1980s and a decrease thereafter, on the order of 5 % from the late 1980s to 2002. (notrickszone.com)
This is the process whereby solar changes alter global cloudiness so as to change the amount of energy entering the oceans and thereby skew the balance of ENSO between El Nino warming or La Nina cooling: (notrickszone.com)
Thus there is a back and forth in global cloudiness as the Sun's activity level changes over the decades and centuries — such as during the period covering the Medieval Warm Period, the Little Ice Age, and the current warm period — through latitudinal shifting of the jet stream tracks and permanent climate zones. (newclimatemodel.com)