Ozone depletion on the surface of the cloud crystals is far different from when it occurs in atmosphere. These conditions have led to ozone hole formation in Antarctica. This hypothesis was decisively confirmed, first by laboratory measurements and subsequently by direct measurements, from the ground and from high-altitude airplanes, of very high concentrations of chlorine monoxide (ClO) in the Antarctic stratosphere. Alternative hypotheses, which had attributed the ozone hole to variations in solar UV radiation or to changes in atmospheric circulation patterns, were also tested and shown to be untenable. Meanwhile, analysis of ozone measurements from the worldwide network of ground-based Dobson
Views of Lyndon LaRouche and the LaRouche movement Science & Technology", which conducted what has been called "a very effective campaign of misinformation on the issue of ozone depletion", published "The Holes in the Ozone Scare" in 1992. The book, by LaRouche followers Rogelio Maduro and Ralf Schauerhammer, said that chlorofluorocarbons (CFCs) were not destroying the ozone layer and opposed the proposal to ban them. It asserted that most chlorine in the atmosphere came from oceans, volcanoes, or other natural sources, and that CFCs were too heavy to reach the ozone layer. It went on to say that even if the ozone layer were depleted there would not