The other threat above
Protecting ozone layer requires national and global action
Even as the world grapples with the threat of global warming and climate change, attention must be paid equally to another atmospheric phenomenon — the damage to the Earth’s ozone layer that shields Earth-dwellers from the Sun’s harmful ultraviolet radiation. Depletion of the ozone layer has reached an unprecedented level over the Arctic this spring, reports the World Meteorological Organisation (WMO). Ominously, it also warns that if the ozone-depleted area moves away from the pole and towards lower latitudes, one can expect ultraviolet radiation levels to rise abnormally. These rays can cause dreaded maladies like skin cancer, cataracts and, worse still, degradation of the human immune system. Its ill-effects may be felt in some crops and forms of marine life as well. Though the occurrence of the ozone hole over Antarctica is an annually recurring phenomenon due to a drop in temperature in the stratosphere, the second topmost layer of the atmosphere, what is worrisome is that the ozone column loss this year had reached 40 per cent until March. This is a good 10 per cent higher than the maximum depletion ever recorded before in the entire winter season. The Antarctic winter is not yet over.
The WMO has drawn attention once again to the hazards of the presence in the atmosphere of ozone-destroying substances, such as chlorofluorocarbons (CFCs), halons and other harmful chemicals used in refrigerators, spray cans, fire extinguishers, foams and a host of commonly used household products. Although it is satisfying that the most potent ozone-busters like CFCs have already been discarded the world over under the Montreal Protocol on substances that deplete ozone, the bitter truth also is that these compounds have a long atmospheric life and might, therefore, take decades to dissipate and disappear. Moreover, much of the old-generation, as also over-aged, refrigeration and other equipment is still in use in many underdeveloped countries where it is, in any case, difficult to check the release of ozone-injurious chemicals into the atmosphere because of improper disposal of such equipment.
The issue of elimination of ozone-injurious substances got confounded when, soon after the introduction of hydro-chlorofluorocarbons (HCFCs) as substitutes for CFCs, it was discovered that these were also inimical to the protective ozone layer. Of course, the parties to the Montreal protocol, which has, fortunately, been ratified by all countries, readily agreed to include the phase-out of HCFCs also in this pact. But the time span envisaged for doing so was fairly long — by 2020 for developed countries and 2040 for developing countries. This target seems too liberal, especially considering the latest revelations on ozone depletion. Little wonder that the UN Environment Programme (UNEP) has been demanding accelerated withdrawal of, if not an immediate total freeze on, ozone-busting HCFCs. However, the commercial implications of such a move cannot be disregarded. A large number of industries and millions of manufacturers of HCFC-containing substances will need to switch over to new technologies. Small and medium enterprises account for a sizeable part of the production of such products in developing countries and they will need assistance in terms of resources as well technology in adopting alternative compounds. Developed countries will have to acknowledge their historic responsibility, the way they did in helping developing countries to discard CFCs, and play a similar role in assisting them to expedite discontinuation of the use of HCFCs. Domestic action alone, on their part, will not suffice.