Ozone holes

Describes the success of the fight against Ozone

Depletion but warns against complacency

When scientists first published their discovery of how chlorofluorocarbons (CFCs) depleted the stratospheric ozone layer in 1974, they started a revolution not just in industry but also in international cooperation between governments, scientists, United Nations organizations and the media. The story of depletion of the ozone layer is now well known. The thin layer of the gas in the stratosphere efficiently screens out excessive ultraviolet radiation from the sun and allows through just enough to sustain life on Earth. More ultraviolet radiation leads to a range of effects, 

including skin cancers, eye cataracts, loss of immunity and reduction of plant yields.

CFCs, invented in 1928, are non-toxic to human beings, non-flammable, long-lived and versatile. These apparent ‘wonder gases’ became used in many industries such as refrigeration, air conditioning, fire fighting and metal cleaning. But scientists reported that they would eventually reach the stratosphere and destroy the ozone layer. Unless the use of the very profitable CFCs was phased out throughout the world, all life would be in danger.

UNEP’s Role:

UNEP, in collaboration with the World Meteorological Organization, catalysed the world’s governments to agree to the Vienna Convention on the Protection of the Ozone Layer in 1985 and Montreal Protocol on Substances that Deplete the Ozone Layer in 1987. The Convention is a framework of  

intentions while the Protocol lays down a timetable for phasing out 95 chemicals by all its Parties. It provided a period of grace to developing countries in recognition of their difficulties in transforming their industries to ozone-friendly technologies. And since 1991 there has been a Multilateral Fund, to which the developed countries contribute, to help them.

Humanity must be forever watchful to ensure that ozone-depleting substances are banished from the world

• The latest scientific assessment found that the abundance of ozone-depleting compounds in the lower atmosphere peaked in 1994 and is now slowly declining.

• Scientists predict that ozone depletion will peak over the next two decades.

• If there had been no Montreal Protocol, there would now be five times as much chlorine in the atmosphere and about 10 times as much ozone depletion. As a result, there would have been many more millions of cases of skin cancer and eye cataracts.

These positive developments instil confidence that the Montreal Protocol will succeed in protecting the ozone layer. But confidence should not lead to a complacent assumption that the problem has been solved. We must remember to negotiate carefully the potholes on the road ahead:

• Ozone-depletion will peak in a few years and the ozone layer recover gradually only if the Montreal Protocol is fully implemented.

• Global warming could adversely affect the ozone layer.

• The Multilateral Fund will have to continue to be replenished each year until the task is completed. ‘Donor fatigue’ or complacency should not divert funds.

• There is a danger of new ozone-depleting chemicals, not controlled by the Protocol, being introduced into the market. The Parties are now considering ways to tackle this.

• Illegal trading in CFCs could cause backsliding by some industries.

Clearly humanity must be forever watchful to ensure that ozone-depleting substances are banished from the world. New technologies must be screened continuously to ensure that they are ozone-safe. The extraordinary spirit of cooperation of governments, scientists, technologists, media and the United Nations organizations must continue until the objective is achieved. Eternal vigilance is the price of a safe world.