Executive Summary of the Ozone Trends Panel Report

Abstract

The report evidently focuses on global aspects of ozone, and the Antarctic ozone hole is just one part. But it is mainly in the Antarctic, where the extreme cold and unique atmospheric circulation of the southern spring occur, that the evidence for drastic decreases in ozone is unequivocal and where, because of direct measurements of the chemical composition of the statosphere during the Antarctic ozone expeditions, the primary responsibility for ozone depletion can be assigned to CFCs. Small decreases in ozone have been found over the rest of the globe, but they are not yet alarming since they are comparable to natural variations. In fact, most of the decrease in ozone in the Northern Hemisphere from 1979 to 1985 appears to have been associated with the 11-year sunspot cycle and with the reduction in ultraviolet radiation emitted from the sun during that period. As well, previously published reports of much larger decreases in ozone amounts were biased by drift in the calibration of the satellite instruments used, as the executive summary explains.