Stephen Montzka of the National Oceanic and Atmospheric Administration in Boulder, CO reported at the December 1995 meeting of the American Geophysical Union that concentrations of atmospheric chlorine, the prime agent for loss of stratospheric ozone, are declining in response to a decrease in CFC production prompted by the 1987 Montreal Protocol to Protect the Ozone Layer. Estimates are that the Antarctic ozone hole could recover to the 1979 level by the year 2050. However, Ronald Prinn of MIT has found that bromine compounds are increasing in the atmosphere, and the bromine atom, although much less abundant than chlorine in the stratosphere, is 40 times more potent than chlorine in destroying ozone.

Richard A. Kerr, 1996: Ozone destroying chlorine tops out. Science 271, 32.

E. S. Takle
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