Recent changes in the production and global atmospheric emissions of chlorodifluoromethane (HCFC-22)

The atmospheric concentrations of chlorodifluoromethane (HCFC-22) have been continuously measured for over a decade in long-term monitoring experiments. Comparison of these data with the industrial and regulatory databases of production and sales indicates that containment of this material is improving and its rate of emission, relative to the quantities produced and in service, is falling. In this paper, we reconcile the results of long-term monitoring with emissions calculated from activity (as global sales into the categories of end-use) and identify the principal changes that have occurred in the overall emission functions.