Unlike the Kyoto accord on climate change, which is set to expire this year without delivering much, the Montreal Protocol on safeguarding the earth’s protective ozone layer stands out as a spectacular success. This agreement, which celebrated its 25th anniversary on September 16, helped phase out over 98 per cent of the world’s ozone-depleting substances — notably chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFCs), used in refrigeration equipment, hairsprays, foams, fire extinguishers, etc. It has not only averted further damage to the ozone layer, but has also put it on the path to recovery. The ozone layer, a dense band of ozone found in the second-highest layer of the atmosphere, shields the earth from the sun’s harmful ultraviolet radiation — which could otherwise cause skin cancer and cataract, besides weakening the immune system.
The unrestricted use of ozone-injurious substances prior to the Montreal accord in 1987 was eroding the ozone layer by four to five per cent every decade. This had created two wide holes in the layer, over Antarctica and the Arctic. A business-as-usual approach would have led to the widening of the holes to 10 times their current size by the middle of this century. Luckily, this process has now been effectively reversed, raising the hope that the layer will be largely repaired in the next five decades. By some estimates, nearly 19 million additional cases of skin ailments and over 130 million cases of eye diseases have been averted, saving trillions of dollars of health expenditure. In addition, ozone-damaging substances were also formidable sources of greenhouse gases; cutting back on their use is estimated to have prevented nearly 25 billion tonnes of carbon dioxide from being released into the atmosphere between 1990 and 2000.
Of course, reclamation of the ozone layer is not complete. CFCs and HCFCs have a long atmospheric life and may take decades to dissipate and disappear from the environment. More importantly, the hydro-fluorocarbons (HFCs), which are being used now as a replacement for CFCs and HCFCs, contribute to climate change, albeit to a much lower degree. These, too, would thus need to be replaced by even safer chemicals. Fortunately, the global community has agreed to do so under the Montreal Protocol itself.
But perhaps the most important lessons from the implementation of the Montreal Protocol are for the fight against global warming. Like the Montreal pact, which was ratified by all countries without any exceptions, the successor to the Kyoto agreement on climate change, too, will need universal participation and political commitment — non-participants like the US or China could again spoil the show. China will have to sign up as the world’s largest emitter, and developed countries like the US will have to make adequate financial and technical assistance available to the developing world, to enable it to reduce harmful emissions — just like the technical and other assistance worth $2.8 billion they provided to discard CFCs. Without unanimity and transfers, the fight against warming will not be as successful.
