By Dr. Konthoujam Khelchandra Singh
The United Nations` (UN) International Day for the Preservation of the Ozone Layer is celebrated on 16 September each year. This date has been designated by the United Nations General Assembly in its resolution 49/114, to commemorate the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987. This commemoration around the world offers an opportunity to focus attention and action at the global, regional and national levels on the protection of the ozone layer. The theme for this year’s celebration “A healthy atmosphere, the future we want.” emphasises the extraordinary collaborations and environmental benefits achieved by the world governments through the operation of Montreal Protocol. The Vienna Convention for the Protection of the Ozone Layer and its Montreal Protocol on Substances that Deplete the Ozone Layer are dedicated to the protection of the earth’s ozone layer. Altogether, 197 countries have ratified the treaties in United Nations history, and have, to date, enabled reductions of over 97% of all global consumption of controlled ozone depleting substances.
On this day classroom activities that focus on topics related to the ozone layer, climate change and ozone depletion are organized to increase the awareness levels were usually held in different schools, colleges etc. Some teachers use educational packages from the UN Environment Programme (UNEP) that have been specifically tailored to address topics about the earth`s ozone layer. Other activities that are organized by different community groups, individuals, schools and local organizations across the world include: the promotion of ozone friendly products; special programs and events on saving the ozone layer; the distribution of the UNEP`s public awareness posters to be used for events centered on the International Day for the Preservation of the Ozone Layer; and the distribution of awards to those who worked hard to protect the earth`s ozone layer.
Ozone is a gas that is naturally present in our atmosphere. Each ozone molecule contains three atoms of oxygen and is denoted chemically as O3. Ozone is found primarily in two regions of the atmosphere. About 10% of atmospheric ozone is in the troposphere, the region closest to Earth (from the surface to about 10–16 Km (6–10 miles)). The remaining ozone (about 90%) resides in the stratosphere between the top of the troposphere and about 50 Km (31 miles) altitude. The large amount of ozone in the stratosphere is often referred to as the “ozone layer”. Ozone is formed throughout the atmosphere in multistep chemical processes that require sunlight. In the stratosphere, the process begins with an oxygen molecule (O2) being broken apart by ultraviolet radiation from the sun. In the lower atmosphere (troposphere), ozone is formed by a different set of chemical reactions that involve naturally occurring gases and those from pollution sources.
The distribution of total ozone over the Earth varies with location on timescales that range from daily to seasonal. The variations are caused by large-scale movements of stratospheric air and the chemical production and destruction of ozone. Total ozone is generally lowest at the equator and highest in Polar Regions. The amount of ozone in the atmosphere is measured by instruments on the ground and carried aloft on balloons, aircraft, and satellites. Some instruments measure ozone locally by continuously drawing air samples into a small detection chamber. Other instruments measure ozone remotely over long distances by using ozone’s unique optical absorption or emission properties.
On the occasion of the observation of World Ozone day 2013, let me highlight some of the key achievements of the Montreal Protocol to date as released by the UNEP, Ozone secretariat. 1) Truly global participation: As noted above the Montreal Protocol is the only treaty ever to achieve universal ratification; it thus demonstrates the world’s commitment to ozone protection and, more broadly, global environmental protection. 2) Healing the ozone layer: Results from continuing global observations have confirmed that atmospheric levels of key ozone depleting substances are going down and it is believed that with continued, full implementation of the Protocol’s provisions the ozone layer should return to pre-1980 levels by the middle of this century. 3) Achieving major reduction goals: By 2010 virtually all Parties had reported compliance with their phase out obligations in respect of CFCs, halons, carbon tetrachloride, methyl chloroform, n-propyl bromide and chlorobromomethane. As a consequence, the Protocol has now led to the phase-out of 98 per cent of the historic levels of production and consumption of ozone-depleting substances. 4) Supporting developing countries: With the assistance of the Multilateral Fund for the Implementation of the Montreal Protocol developing countries had, by mid-2011, permanently phased out over 260,000 tonnes of ozone depleting substances that had been used to produce various products. 5) High rates of compliance: Taking into account all parties to the Protocol and all their phase-out commitments, the parties have achieved a compliance rate of over 98 per cent. Further, in the process of phasing-out many countries, both developed and developing, have met their phase-out targets well ahead of schedule. 6) Health benefits: Controls implemented under the Montreal Protocol have enabled the global community to avoid millions of cases of fatal skin cancer and tens of millions of cases of non-fatal skin cancer and eye cataracts. The United States estimates that by the year 2065 more than 6.3 million skin cancer deaths will have been avoided in that country alone and that efforts to protect the ozone layer will have saved it an estimated US$4.2 trillion in healthcare costs over the period1990–2065. In addition, in 2011 the United States Environmental Protection Agency estimated that more than 22 million Americans born between 1985 and 2100 would avoid suffering from cataracts thanks to the Montreal Protocol. 7) Climate benefits: The Protocol has also delivered substantial climate benefits. Because most ozone depleting chemicals are also greenhouse gases, the Protocol has already averted greenhouse gas emissions equivalent to more than 135 billion tonnes of carbon dioxide. These significant reductions make the Montreal Protocol one of the prime contributors to the fight against global warming
The challenges ahead for Montreal Protocol on Substances that Deplete the Ozone Layer are: While the results of the Protocol to date are impressive, the fact remains that a great deal of additional action will be essential to ensure that the ozone layer remains safe for this and future generations. Most important, the Parties to the Protocol will have to maintain their momentum to complete the job. Indeed, science tells us that this is essential to ensure the protection of the ozone layer for this and future generations. This work will not be easy. The continuing work under the Protocol includes the phasing out of hydrochlorofluorocarbons (HCFCs), which also contribute to global warming; the environmentally friendly phase-out of this group of chemicals is likely to prove a real challenge for both developed and developing 11countries. On the other hand, this phase out presents real opportunities for the Parties to achieve both ozone and climate benefits, and also great advances in energy efficiency. Further, a widely used alternative to HCFCs is Hydrochloroflurocarbons or HFCs, some Parties have formally proposed that these substances (which are currently among the basket of gasses included in the Kyoto Protocol) be brought under the Montreal Protocol phase-out regime.
In addition to the phase-out of HCFCs, the Parties must complete the phase-out of methyl bromide. While much progress has been made to phase-out the use of this once widely used agricultural fumigant, it is apparent that the final phase-out will not be easy and will require sustained effort from the global community. Finally, on the chemical side, it will become more urgent to find alternatives for the remaining use of halons in new airframes and military equipment as stocks of halons begin their inevitable decrease over the coming years. Key questions also remain about how to deal, in an environmentally sensitive manner, with the very large banks of ozone-depleting substances currently in use systems or inventories. These substantial stocks will, unless acted upon, eventually be emitted over the coming decades. Finally, in relation to chemical controls, the Parties to the Protocol must be on the lookout for new chemicals with the ability to deplete the ozone layer, and new issues which could threaten the global communities hard won gains. In that regard, it is important to remember that many had believed the ozone issue to be solved by the original 1987 Montreal Protocol agreement, only to find a short time later that the threat was significantly greater than originally anticipated. While many challenges remain, it is hoped that the continuing efforts to protect the ozone layer will move forward in the same spirit of dedication, cooperation and innovation that characterized the initial efforts, and that the Protocol will go on to achieve its goal of protecting the ozone layer for time to come.
(Author is an Assistant Professor, Department of Environmental Science, PUC Campus, Mizoram University, Aizawl-796001, can be contacted at: [email protected])