Role of chlorine in stratospheric chemistry

The chlorofluorocarbons (CFCs) are industrial chemicals used as solvents, refrigerants, plastic foam blowing agents, etc. These compounds are eventually released to the environment; they slowly drift into the stratosphere, where they decompose, initiating a catalytic process involving chlorine free radicals and leading to ozone destruction. The stratospheric ozone layer is important for the earth's energy budget, and it shields the surface of the earth from ultraviolet radiation from the sun. very significant depletion of the ozone layer has been observed in the spring months over Antartica during the last 10-15 years. Laboratory experiments, model calculations and field measurements, which include several aircraft expeditions, have yielded a wealth of information which clearly points to the CFCs as the main cause of this depletion.