In 1994, the UN General Assembly proclaimed September 16 the International Day for the Preservation of the Ozone Layer, commemorating the date of the signing, in 1987, of the Montreal Protocol in the Vienna Convention on substances that deplete the ozone layer. Bangladesh has been observing the day since 1990 following signing of the protocol in the same year. 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 closure of the hole in the ozone layer was observed 30 years after the Montreal Protocol was signed. Due to the nature and characteristics of the gases responsible for ozone depletion, their chemical effects are expected to continue for between 50 and 100 years. The ozone layer which surrounds the earth at a height of about 25km protects life on earth by absorbing some of the radiation from the sun thus preventing harmful ultra-violet (UV) rays from reaching the earth's surface. Decreases in ozone amounts lead to increases in UV radiation. Exposure to UV irradiance reaching the Earth's surface is also affected by the amount of cloud cover and by the altitude above sea level. The increase in UV rays has been linked to an increase in some types of skin cancers, cataracts, lower plant productivity, and deterioration in certain forms of marine life.
Ozone Depleting Substances (ODS) are certain man-made chemicals containing Chlorine and Bromine, which have a high potential to deplete the ozone layer through chemical interactions in the earth's stratosphere. Examples of ODS include chlorofluorocarbons (CFCs) used in refrigerators, air-conditioning units foam products, and aerosol sprays and halons used in fire extinguishers.
In this year the COVID-19 pandemic took back many things and has brought such a social and economic hardship, the ozone treaties' message of working together in harmony and for the collective good is more important than ever. The slogan of the day, 'Ozone for life', reminds us that not only is ozone crucial for life on Earth but that we must continue to protect the ozone layer for future generations. Earth's ozone layer is healing, after COVID-19 decreases pollutions rate and that really contribute to healing ozone layer. Some expert says that the coronavirus outbreak hastens the recovery of the ozone layer by decreasing the pollution.
The hole had been about three times the size of Greenland. A "record-level" ozone hole over the Arctic - the biggest since 2011, has now closed, the UN World Meteorological Organisation (WMO) said. Despite coronavirus lockdowns resulting in a significant reduction in air pollution, some scientist said, the occurrence of the hole healing "was completely unrelated to COVID".
A report from the United Nations says that the hole in the ozone layer could be totally healed by the 2060. In some areas of the world, it could be as soon as 2030. UN Secretary-General Antonio Guterres has said a healthy ozone layer and climate are essential to meeting all of the Sustainable Development Goals (SDGs). "Phasing these out could reduce global warming by up to 0.4°C this century. As industry redesigns appliances to replace HFCs, it is also essential to improve their energy efficiency to further reduce their impact on the climate," Guterres said. He termed the Montreal Protocol a 'milestone' for the people and the planet.
In Bangladesh ozone depleting substances, all imported gases, were used in pharmaceutical production, refrigeration, air-conditioning, readymade garments and aerosol manufacturing industries. As a signatory of Montreal Protocol, a global deal to phase out ODS, Bangladesh along with other developing countries cannot import and use of any kind of ODS gases of chlorofluorocarbon (CFC) group, carbon tetrachloride and methyl chloroform after December 2009, except for essential uses.
Bangladesh was the first among the developing countries that had completely phased out hydrochlorofluorocarbon-141b gas from the foam sector of the refrigerator assembling industries. With almost 8.2 per cent GDP growth, Bangladesh is experiencing increasing demand for appliances having ODS in air conditioners and refrigerators. Despite the challenges of this increasing demand, Bangladesh is doing well in the phase out activities of ozone depleting substances, and it is one of the most successful countries.
The phase-out of controlled uses of ozone depleting substances and the related reductions have not only helped protect the ozone layer for this and future generations, but have also contributed significantly to global efforts to address climate change; furthermore, it has protected human health and ecosystems by limiting the harmful ultraviolet radiation from reaching the earth. Let this International Day for the Preservation of the Ozone Layer be an inspiration towards greater goals on cooling, as part of Climate Action.
Professor Dr. Ahmad Kamruzzaman Majumder is Dean, Faculty of Science, Chairman, Department of Environmental Science, Stamford University Bangladesh, Founder and Director, Centre for Atmospheric
Pollution Studies (CAPS).