The Daily Sun | 23 September 2018

September 16 was the International Day for the Preservation of the Ozone Layer 2018 or simply the International Ozone Day. Unified efforts are being made to maintain the ozone level and in this goal, the first attempt was the Vienna Convention held on 22 March 1985 in Austria. Every year the day is celebrated to create public awareness through various programmes focusing on a specified theme. Most of the countries signed in Montreal Protocol held in 1987 to reduce the ozone-depleting gases which came into force since 1st January 1984. Bangladesh is also a signatory of this treaty since 1990 and working with the global community activity.

In 1930, two French physicists Charles Fabry and Henri Buisson first discovered the ozone layer. The ozone layer is a layer of earth’s atmosphere that has relatively high levels of ozone gas. This layer is mainly located in the lower part of the stratosphere. The thickness of this layer depends on locations and seasons. Stratosphere consists of 90 per cent of the atmosphere. Ozone concentrations are about 20 to 40 kilometers (66,000 and 131,000 feet), where they are the best among the ranges from about 2 to 8 parts per million. If all parts of this ozone are compressed by the air pressure of the sea level, it will be only 3 millimeters thick. Later on, a lot of research was done on this. Scientific studies have shown that the presence of increasing chlorofluorocarbons or CFCs in the atmosphere is rapidly eroding the ozone layer. The depletion of Ozone layer has a profound negative effect on animal and plants since it allows the ultraviolet ray to enter the earth’s atmosphere.

Depletion of the ozone layer can lead to genetic mutation of the human body, skin cancer, early aging, eye problems like cataracts, and harmful diseases that damage the body’s regular immune system. In addition, UV rays affect the actual growth of plants, cause to leaf fallen disease, genetic mutation as well as intake of nutrients and their transport. At the same time, it also has an intimate relationship with climate change having a bad impact on the marine environment.

Ozone-layer Depletion is also increasing the greenhouse effect. Increasing technologies and modern science inventions are improving the comfort of living but at the same time, these technological advancements are contributing to the rise in temperature and greenhouse gases. Due to excessive use of fossil fuel, (coal, petroleum etc.) in the industries and factories, the carbon dioxide, along with other greenhouse gases emitted in the environment, is increasingly getting trapped inside the atmosphere. Sun is the main source of energy. The heat comes in the form of wavelength of sunlight, and after it’s absorption by the living and the non-living entities in the earth, the rest of the energy is reflected back. But instead of leaving, the energy gets trapped inside greenhouse gases eventually increasing the temperature of the earth and this is known as Global Warming. According to a team of Chinese researchers, by the end of the 21st century, the earth’s temperature will increase by 4° Centigrade compared to the pre-industrial level.

Bangladesh also decided to work together with the world to protect the ozone layer and restore the balance of the environment. Thus, Bangladesh signed the Montreal Protocol in 1990. The Montreal Protocol is a worldwide agreement that was finalised in 1987, which aims to protect the stratospheric ozone layer by measuring the production of ozone-depleting substances (ODS). The hole of the Antarctica region is replenished again. According to environmental scientists, the whole ozone layer will be replenished by 2050 to 2070 as like as 1980. As a result, the theme of International Day for the Preservation of the Ozone Layer, 2018 has been titled as “Keep cool and carry on Montreal Protocol” and disseminated in six official languages of United Nations.