Ozone hole is a word related with depletion of Ozone layer that exists in stratospheric part of atmosphere and the threat it poses to life on the earth.
The phenomena of ozone hole first reported in 1985 over Antarctica and then reported from the Arctic and even from the temperate latitudes. There is a general agreement among the scientists that a thin layer of ozone exists in atmosphere at the height of 25-35 kilometers above the earth’s surface.
Ozone is a very vital gas in the atmosphere. It is made up three atoms of oxygen while ordinary oxygen is made up of only two atoms. The formation of ozone takes place in the upper stratosphere when an oxygen molecule is broken into two atoms by ultra-violet radiation and the free unstable atoms combine with two other oxygen molecules. This results in the formation of two molecules of ozone which comprise three oxygen atoms each.
In facts, the ozone layer acts as a filter for the ultraviolet rays of the sun. The presence of this layer is undoubtedly a boon to humanity. In absence of ozone in the upper atmosphere, the harmful ultraviolet radiation would reach the earth in large amounts. Such an event could lead to disastrous consequences. This radiation in excessive quantity would render men and animals blind. This would also burn man’s skin, increase the incidence of skin cancer, and destroy many microscopic forms of life. In addition, it could also damage flora on our earth.
According to World Meteorological Organization report on anthropogenic modification of climate, a continued released of cholofluro carbon (CFC) into the atmosphere is resulting in the significant reduction in stratospheric ozone.
The environmentalists have expressed grave concern that the emission of nitrogen oxides by a large number of supersonic transport aeroplanes may cause deterioration of ozone layer. Thus, industrial chemicals released by man are now destroying stratospheric ozone faster than nature can replenish it, posling serious threat to life on our planet.
To protect the ozone layer the International community has taken unprecedented steps to control and ultimately ban the production of CFCs and other Ozone depleting substances such as halons and carbon tetrachloride by the year 2000.
The Vienna Convention and the subsequent Montreal Protocol on substances that deplete the Ozone layer, adopted in 1987 and strengthened in 1990, set strict timetables for phasing out CFCs and other Ozone depleting substances by 2000, It has also established rules governing international trade in ODS and the products based on these materials.
As developing countries face a formidable challenge in reforming their CFC use as they lack the financial and technological means available to them and so developing countries have been allowed a 10 years grace period (i.e. upto 2010) for full compliance to the Montreal Protocol.
The schedule for phasing out different ozone depleting substances for all the participating countries was reviewed by the parties to the Montreal Protocol in 1985. The Protocol also provided for a multilateral fund to assists developing countries to cover their incremental costs in eliminating £FCs or ODS and for this India will get 1.9 billion dollar under the protocol for using ODS substitute.