THE CHEMISTRY OF STRATOSPHERIC OZONE - ITS RESPONSE TO NATURAL AND ANTHROPOGENIC INFLUENCES

The current rapid changes in the composition of the atmosphere reflect both the metabolism of the biosphere and the broad range of influencing human activities. However, the only known sources of CFCs are industrial. In predicting future changes in ozone depletion and global warming it is necessary to understand the role of the biosphere in regulating emissions as well as future industrial emissions. This paper discusses theoretical predictions and trends in global ozone concentrations from 1969-1986. Antarctic and Arctic ozone trends and the global implications of the Antarctic ozone hole are described in detail. It is concluded that even if the control measures of the Montreal Protocol are implemented by all nations, the atmospheric abundance of chlorine will at least double during the next few decades. Future global ozone depletion could be larger than originally predicted because the PSC-induced chemical reactions that cause ozone depletion were not included in the stratospheric ozone assessment models on which the Montreal Protocol was based. To return the Antarctic ozone layer to its natural state will require very strong measures, including a complere phase out of all fully halogenated CFCs, halons, carbon tetrachloride and methyl chloroform, as well as careful use of HCFC substitutes. © 1990.