Shrinking Ozone Hole

For a change, there is some good news on the environment front. The ozone hole, which so caught headlines in the Eighties, has been repairing itself thanks to corrective human action. It is a significant development, showing as it does what a “careful mix of authoritative science and collaborative action” can deliver, in the words of UN Environment head Erik Solheim recently. He was referring to the string of initiatives taken under the Montreal protocol of 1987. Located 10-40 kms over the Earth’s surface, the ozone layer acts as a protective shield — blocking the sun’s high energy ultraviolet rays which can trigger harmful mutations in living cells, cause skin and other cancers and damage crops. By the early Seventies, studies had established how some chemicals like chlorofluorocarbons (CFCs) used in refrigerants, aerosols and foam insulations — were flying up the stratosphere and attacking ozone molecules. This caused thinning of the ozone layer, which at its worst showed a depletion of 10 percent by the turn of the millennium. In 2006, the ozone hole over the South Pole was measured at 29.6 million sq km. Fortunately, nations came together in 1987 at Montreal and agreed to phase out the use of ozone depleting substances. In the latest review of that pact, the UN has reported that the ozone layer has been replenishing itself at the rate of 1-3 percent every decade. If this progress is kept up, the ozone hole over northern hemisphere and mid-latitude region should heal completely by the mid-2030s, followed by southern hemisphere by the 2050s and the polar regions by 2060. It has been estimated that had the world community done nothing last century, two-thirds of the ozone layer would be destroyed by 2065. The threat was taken seriously and timely action followed, making the Montreal protocol a successful multilateral agreement. The progress has not been entirely smooth however, with new technology showing that some country or countries in East Asia have been emitting a banned chemical CFC-11 since as late as 2012. Experts are thus warning it is too early to claim that the tide has been completely turned. In fact, the world community has been finding it harder to forge any consensus on meeting environmental threats, most notably in limiting emission of greenhouse gases which are heating up the Earth and triggering extreme weather phenomena. By January 1 next year, the Kigali amendment to Montreal Protocol will come into force, setting the target for 80 percent reduction in use of atmosphere-warming gases in fridges, air conditioners and related products. So far, only 58 nations have come on board. On one hand, there is greater volume and precision of scientific data in 21st century about climate change, while on the other, nations are growing more intransigent about making the sacrifices needed. In one of his last messages before he passed away in March this year, Stephen Hawking sounded a warning about the future of education and science, of “a global revolt against experts, and that includes scientists”. While science is yet to overcome major global challenges like overpopulation, climate change, deforestation, degradation of the oceans and species extinction, “we are in danger of becoming culturally isolated and insular, and increasingly remote from where progress is being made,” he had said. For the young inheriting a stressed Earth, the great cosmologist’s parting advice was ‘not to give up, unleash the imagination and shape the future’. Three decades back, it was such a faith in science and can-do attitude that have now made the world breathe a little easier over ozone depletion. There is no reason why this cannot be invoked for bigger challenges ahead.