The Ozone Protection Section fulfils Australia's international obligations under the Montreal Protocol on Substances that Deplete the Ozone Layer. Ozone is a naturally occurring molecule containing three atoms of oxygen. Ozone Layer Depletion - Causes and Effects Concerns about the depletion of the ozone layer exist because the ozone layer reduces the amount of harmful ultraviolet radiation that reaches the earth's surface. The ozone layer is also an important part of the global atmosphere-climate system in which present day living organisms, including humans, have evolved. Any significant change to this layer can have far-reaching consequences for human health.
Ozone depleting substances also contribute to varying extents to the greenhouse effect .
In addition to this general thinning, more dramatic damage occurs over Antarctica each Spring when the ozone 'hole' forms. In 1998 Antarctic ozone 'hole' was 27.3 million square kilometres in area. The prospects for the long term recovery of Antarctic ozone are good. Non-essential consumption of the major ozone depleting substances in the developed world slowed during the early 1990s and ceased in 1996. Stratospheric chlorine levels should return to pre-ozone hole levels by about 2050.