Wednesday, May 26, 2010

25th Anniversary of Ozone Hole Discovery

25 years ago in May 1985, scientists from the British Antarctic Survey (BAS) officially discovered the now controversial hole in Earth's ozone layer. The feature, which has expanded and contracted since its discovery, has been responsible for large losses of ozone in Earth's atmosphere over Antarctica.

The discovery of the ozone hole alerted the world to a major environmental threat as the accumulation of chlorofluorocarbons (CFCs) used in 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.

In good news, the ozone layer depletion seems to be on a dramatic upswing and levels of ozone are expected to continue to reach safer levels in the coming decades.