World Ozone Day recognises 20 years of international cooperation
16 September 2007
Since 1995, September 16 has been internationally celebrated as World Ozone Day. On this day in 1987, the landmark international treaty to protect Earth's ozone layer known as the Montreal Protocol was signed. The Montreal Protocol is a global agreement to limit the production and release of certain man-made substances which cause harmful effects to the protective blanket of ozone in the stratosphere (10–50 km above the Earth's surface).
After 20 years of international action, there are clear signs that the Montreal Protocol is having the required effect
- atmospheric levels of key ozone depleting substance have declined
- there are initial indications of ozone recovery in certain parts of the atmosphere
The most profound display of detrimental human influences on ozone was the recognition in the 1980's of the 'ozone hole' over Antarctica. During the past three decades, the action of man-made chemicals and the special meteorological conditions found in the winter polar stratosphere, particularly over Antarctica, have resulted in dramatic episodes of enhanced ozone destruction during spring. The scientific study of this phenomenon provided the basis for the swift cooperative action that lead to the Montreal Protocol.
Twenty years on, the international scientific community is still intensively examining human influences on ozone to ensure that we can accurately assess the state of the atmosphere and the effectiveness of our actions.
The Antarctic measurements include a network of 9 stations that are measuring the vertical distribution of ozone with balloons. Australia's Davis station is contributing ozone and other atmospheric measurements to the ORACLE-O3 project. The programme is operated by the Australian Antarctic Division and the Australian Bureau of Meteorology.
- Information on Australia's contribution to IPY ozone research (Australian Antarctic Magazine 12: 12–13, 2007)
- Montreal Protocol website
- Australian Department of the Environment and Water Resources ozone website
- United Nations Environment Programme World Ozone Day information
- Current state of the Antarctic ozone hole at NASA