14 DAY TRIAL // Since an international ban on ozone-destroying CFCs (Chlorofluoro compounds) in 1987, the ozone hole over Antarctica has started to repair itself, but the process will take much longer than anticipated, researchers claim.
According to BBC, the latest modeling predicts the protective gas layer found in the stratosphere will not recover its health until about the year 2065.
"The reservoirs of ozone-depleting chemicals found in old fridges and air-conditioning systems may be greater than anticipated, and if this continues into the future then the projection of ozone hole recovery in 2050 may have to be extended," said Dale Hurst, from the US National Oceanic and Atmospheric Administration.
On 6 December, after satellite measurements, NASA said that this year, the hole was 24.3 million square kilometers at its largest. The figure is slightly larger than last year's peak, but still smaller than the 26.4-million-square-kilometre record of 1998, a Nature article said.
Although the concentration of ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation from the Sun.
About 90% of the ozone in our atmosphere is contained in the stratosphere, the region from about 10 to 50km above Earth's surface. Ten percent of the ozone is contained in the troposphere, the lowest part of our atmosphere where all of our weather takes place.Ozone concentrations are greatest between about 15 and 40 km.