Ongoing monitoring by the British Antarctic Survey, which alerted the world to the hole in the protective ozone layer over the South Pole in 1985, has concluded that the hole has now stabilized. Thinning of the ozone that surrounds the Earth provided the first clear evidence that man could damage the global environment on a colossal scale. “It also provided the first case of concerted international action to counteract such an effect,” says Richard Stolarski, a research scientist with NASA, who has reviewed the history and science related to the phenomenon.

Scientists had discovered that the accumulation of chlorofluorocarbons (CFCs) used in industrial solvents, refrigeration, air conditioning systems and aerosols were depleting the blanket of ozone that surrounds the Earth. Action by United Nations governments around the world led to the 1987 Montreal Protocol, effectively phasing out use of such chemicals. Today, scientists predict that, with continued care, Antarctic ozone levels will return to their 1950s levels by about 2080.