Ozone Layer Current Affairs

16 September: International Day for Preservation of Ozone Layer

The International Day for Preservation of Ozone Layer (or World Ozone Day) is observed every year on September 16 for the preservation of the Ozone Layer. This year, the theme for the Day is ‘Caring for all life under the sun’.

The day was designated by the United Nations General Assembly (UNGA) on December 19, 1994. Its observance commemorates the date in 1987 on which the Montreal Protocol was signed on substances that deplete the ozone layer. It also is intended to spread awareness of the depletion of the Ozone Layer and search for solutions to preserve it.

Ozone Layer

The Ozone layer is fragile shield of gas which protects Earth from harmful ultraviolet (UV) radiation of Sun and thus helping preserve life on the planet. It contains high concentrations of ozone (O3) in relation to other parts of the atmosphere. Stratospheric Ozone is not harmful, but its presence on land it is harmful. Substances like Chlorofluorocarbons, halons, Carbontetrachloride are responsible for ozone layer depletion.

Montreal Protocol

It is an international treaty designed to protect ozone layer by phasing out production of numerous Ozone Depleting Substances (ODSs) that are responsible for ozone depletion. It was agreed on 26 August 1987 in Montreal, Canada and entered into force on 26 August 1989.

It was followed by a first meeting in Helsinki, May 1989. Due to its universality, Montreal Protocol has helped in recovering the ozone hole in Antarctica. Under it production and consumption of key ODSs like chlorofluorocarbon (CFCs), Methyl Chloroform, CTC halons and Methyl Bromide have been phased-out globally.

Vienna Convention for Protection of the Ozone Layer

It is multilateral environmental agreement agreed upon at the 1985 Vienna Conference and entered into force in 1988. It is one of the most successful treaties of all time in terms of universality. It has been ratified by 197 states (all UN members as well as the Niue, Holy See and the Cook Islands) as well as European Union.

It acts as a framework for the international efforts to protect the ozone layer. These are laid out in the accompanying Montreal Protocol. However, it does not include legally binding reduction goals for the use of CFCs, the main chemical agents causing ozone depletion.

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Black Carbon released by aeroplanes may be affecting ozone, monsoon: Study

According to a recent study by climate researchers, aeroplanes may be ejecting significant amounts of black carbon (BC) which in turn is affecting monsoon,  depleting the ozone layer and quickening glacier melt.

The study was conducted by climate researchers from multiple institutions in India including from the Indian Institute of Science and ISRO’s Vikram Sarabhai Space Centre.

Key Facts

Earlier it was believed that airborne BC is unlikely to travel upward of 4 km and dissipate and settle down in few months under the influence of wind and rain. However, this study shows that such particles exist up to 18 km into the stratosphere, a stable region of the atmosphere.

Given the shape and location of these BC particles, researchers believe they could only derive from emissions from burning of aviation fuel in aeroplanes. As BC particles absorb heat, they warm the surrounding air, become lighter and rise to greater heights by a process called self-lift and persist for longer time in the air.

The airborne BC particles released by aeroplanes possess a problem because they can linger long time, enough to provide a fertile ground for other chemical reactions that can deplete the ozone layer. As, BC particles strongly absorb solar and terrestrial radiation and heats up the atmosphere it can also upset the monsoon system. If deposited on snow, it could accelerate the heating of snow and quicken the melting of glaciers.

Significance of Study: This is the first time that any group of climate researchers in the world has shown that black carbon from aircraft can go to the stratosphere and affect the ozone layer.

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