Until I990 the use of ozone-depleting substances in industry has increased significantly and has led to the depletion of the ozone layer observed by scientists in the 1980s. New data have revealed that the hole in the Antarctic ozone layer which appears each spring is larger than was originally calculated, and there is evidence of a similar role beginning to form over the Arctic. The serious implications for life on earth and human health have resulted in global action to protect the stratospheric ozone layer.