BY VISHAL GULATI Nairobi, March 4 : In the mid-1970s, scientists warned that man-made chemicals in everyday products like aerosols, foams, refrigerators and air-conditioners were harming the ozone layer. At that time, they didn't know the scale of the problem. But in 1985, a hole was confirmed in the ozone layer over Antarctica. The world's natural sun shield, which protects humans, plants, animals and ecosystems from excessive ultraviolet radiation, had been breached. Suddenly, a future blighted by skin cancers, cataracts, dying plants and crops and damaged ecosystems loomed. There was no time to lose. Scientists had raised the alarm and the world listened. In 1985, governments adopted the Vienna Convention for the Protection of the Ozone Layer, which provided the framework for the Montreal Protocol to phase out ozone-depleting substances, including chlorofluorocarbons (CFCs). The Protocol came into effect in 1989 and by 2008, it was the first and only UN environmental agreement to be ratified by every country in the world. The UN Environment Programme (UNEP) played a key role in this successful process. It brokered the Vienna Convention, and since 1991, has hosted the Ozone Secretariat in Nairobi, Kenya. The results have been dramatic. Around 99 per cent of ozone-depleting substances have been phased out and the protective layer above earth is being replenished. The Antarctic ozone hole is expected to close by the 2060s, while other regions will return to pre-1980s values even earlier. Every year, an estimated two million people are saved from skin cancer and there are broader benefits too, as many of the ozone-depleting gases also drive up global temperatures. With pollution threatening the future of the world's oceans, UNEP launched its Regional Seas Programme in 1974. At the time, it was an unprecedented effort to unite countries in a common environmental cause -- and one that would shape future treaties, like the Paris climate change agreement. Today, 150 countries are part of the programme, which is helping to prevent pollution, protect marine animals and chart the effects of climate change on the oceans. These are one the remarkable environmental milestones -- all driven by science and multilateralism Looking back at the glorious 50 years of UNEP, the General Assembly passed what is formally known as UN-Resolution 2997. It would be the last step in the establishment of UNEP, an organisation conceived to spearhead a global effort to minimise humanity's footprint on the planet. During the next five decades, UNEP would take on some of the world's most pressing environmental problems, from climate change to species loss, to pollution. Following the UN Environment Assembly 5.2 (UNEA 5.2), the world's highest-level decision-making body on the environment, a special session called UNEP@50 was held from March 3-4 to commemorate UNEP's 50th anniversary. The special session began with pomp and ceremony just hours after 175 nations signed up to end global scourge of plastic pollution. As per UNEP Executive Director Inger Andersen's first remark after the resolution, "today (March 2) marks a triumph by planet earth over single-use plastics. This is the most significant environmental multilateral deal since the Paris accord". "It is an insurance policy for this generation and future ones, so they may live with plastic and not be doomed by it." Heads of state, ministers of environment and other representatives from 175 nations endorsed the resolution at the UN Environment Assembly (UNEA-5) to end plastic pollution and forge an international legally binding agreement by 2024. The resolution addresses the full lifecycle of plastic, including its production, design and disposal. Tracing the history that how Nairobi came to host the UNEP headquarters. According to a UNEP blog, the genesis of Nairobi's selection can be traced back to 1965 when the city launched an unsuccessful bid to host the UN Industrial Development Organization. This spurred Nairobi to adopt a different approach eight years later in the race to host UNEP. Kenya successfully secured the support of other countries that had bid for UNEP's headquarters, including Mexico City and New Delhi. With this united front, Nairobi's bid was officially adopted on 15 December 1972 during the UN General Assembly's 27th session, which involved all Member States. The bid earned 128 votes in favour, none against and no abstentions. By October 1973, UNEP had set up shop in the Kenyatta International Convention Centre. Two years later, it moved to a new location on an old coffee farm in Nairobi's outskirts, where it remains today. After 50 years of existence, Kenya still regards UNEP as a unique organisation in the UN System that offers the Global South an opportunity to voice its environmental concerns and engage the world for practical solutions. "UNEP is a gem. It is a vehicle through which those of us who live in the South are able to articulate our concerns regarding environmental sustainability," says Ambassador Rachelle Omamo, Cabinet Secretary for Foreign Affairs of Kenya. So what is the next journey of UNEP, its chief Andersen explains by saying: "Our journey will only conclude when we ensure that humanity can thrive without skewing the delicate balance of life on this glorious planet." According to her, a thread that UNEP and the environmental community have thickened, strand by additional strand, into a guide rope strong enough for "us all to grasp". "We must now hold fast to this rope, and follow it into blue skies, azure seas and verdant nature -- thrumming with life in all its forms. Into peace, prosperity and equity. Into a world where humanity lives as part of nature, not above it. "We owe this to our past, to our present and to our future," Andersen added. To mark UNEP's 50th anniversary, a year-long series of activities and outreach events are taking place under the UNEP@50 banner. These recognise the significant progress made on the global environmental matters and address the planetary challenges to come. (Vishal Gulati can be contacted at vishal.g@ians.in) /IANS