Diagnosis of cloud amount increase from an analogue model of a warming world

Using cloud amount records for the continental USA (published), Canada, including parts of the Arctic (in preparation), Europe (published) and the Indian sub-continent (new results), cloudiness changes have been analyzed in the context of the analogue model which compares records of two contrasting 20 yr periods. Cloud amount is found to increase over practically the entire USA, Canada, most of the Indian subcontinent, and parts of Europe in all seasons. These results have been derived for a wide range of climates and considerably strengthen the view that total cloud amount increases in a warming world. It must be recognized that the historical record reviewed here is land-based only, contained within the Northern Hemisphere and excludes many more areas especially the tropics and equatorial regions. -from Authors