In 1969, many nations of the world sent scientists to Antarctica, in an attempt to learn more about the Earth as a whole. Every year since 1969, the hole has reappeared during the southern winter, and each year, the area of the hole has increased. Ozone is formed by the action of ultraviolet radiation on the upper stratosphere. Two American chemists, F. Sherwood Rowland and Mario J. Molina began studying the ozone problem in 1973. Their studies have now continued for over 20 years, and our understanding of the stratosphere has increased greatly as a result of their work.
Stratospheric ozone is known to be the major absorber of ultraviolet radiation.
If the ozone is actually decreasing, it will be a serious problem. The evidence collected showed that the ozone was essentially constant from 1979 through 1990. There is ozone variation in each satellite orbit from high on the daytime side of Earth, to low on the nighttime side, and even these variations hold constant. So at first glance, the problem didn't seem too serious. But increases in the Antarctic ozone hole and evidence of ozone decreases around the north pole indicated that we were playing a dangerous game, an experiment to see if we could destroy enough ozone to damage the Earth.