25th anniversary of the discovery of the ozone hole

Ozone sonde release
Ozone sonde release (Photo: Julian H)

In May 1985, scientists from the British Antarctic Survey (BAS) described their observations of large losses of ozone over Antarctica in the prestigious journal, Nature.

The scientists had been monitoring ozone since the International Geophysical Year of 1957–58. In 1985 they discovered that since the mid 1970s ozone values over Halley and Faraday research stations had been steadily dropping when the sun reappeared each spring. Something in the stratosphere (about 20 km above Earth) was destroying ozone. 

The discovery of the ozone hole alerted the world to the dramatic and major environmental threat. The accumulation of chlorofluorocarbons (CFCs) used in refrigeration and air conditioning systems, and industrial solvents were found to deplete the protective layer of ozone that surrounds the Earth. Action by governments around the world led to the 1987 Montreal Protocol and its amendments, which ensured that production and consumption of CFCs, halons and carbon tetrachloride were phased out by 2000, and methyl chloroform by 2005. All members of the United Nations have now signed the Montreal Protocol. Today, scientists predict that Antarctic ozone levels will return to their 1950s levels by about 2080.

To mark the 25th anniversary of the discovery of the ozone hole, BAS has published a new public information leaflet.

This week's issue of Nature also features the original ozone research paper and a collection of related articles.

You can also read more about ozone research at the Australian Antarctic Division