Whatever Happened to… the Ozone Layer Hole?

When researchers Frank Sherwood Rowland and Mario Molina told the world in 1974 that aerosol hairsprays damaged the part of the atmosphere that protects us from solar ultraviolet radiation, the reactions were not simply disbelief. Soon after, the so-called ozone hole became not only a global concern, but also one of the symbols of the green activism of the 1980s. Whatever happened to… the ozone layer hole?