International Day for the protection of the Ozone Layer

‘Save O₃ur Sky – Be Ozone Friendly' is the theme of this year's International Day for the Protection of the Ozone Layer, being marked on 16 September.

At this time we bring into sharper focus our dedication to protect the ozone layer. It is also an occasion to raise global awareness on the importance of preserving the ozone layer. Ozone-depleting substances and products using them are fast being phased out and replaced with ozone-friendly substances and products. Faster adoption of these alternatives and substitutes will help in quicker repair of the ozone layer.

The phase-out schedule of ozone depleting substances under the Montreal Protocol on Substances that Deplete the Ozone Layer, to which Malta is signatory, is well on course. Over 80 per cent of both production and consumption of these substances has already been phased out and what is left should start diminishing as developing countries move towards implementing the first phase-out measure under the Montreal Protocol – the freeze of both production and consumption of chloroflourocarbons (CFCs) from 1 July 1999. Malta is classified as a developing country under the Montreal Protocol.

In spite of all the actions taken, the ozone layer still remains depleted due to the long life of the substances released over the past five decades and the continuing use of these substances. In addition, the climate change caused by the greenhouse gases may worsen the ozone depletion. Restoration of the ozone layer is expected to be completed around the middle of the next century if all agreed measures under the Montreal Protocol are fully implemented. The international community should continue to be vigilant until the phase-out of ozone depleting substances is completed.

Ozone Molecules (O₃) consist of three oxygen atoms. This poisonous gas is extremely rare in the atmosphere, representing just three out of every 10 million molecules. 90 per cent of ozone exists in the upper atmosphere, between 10 and 50km above the earth. Ozone at ground-level, at the bottom of the troposphere, is a harmful pollutant resulting from automobile exhausts and other sources.

Scientific concern started in 1970 when Prof Paul Crutzen pointed out the possibility that nitrogen oxides from fertilizers and supersonic aircraft might deplete the ozone layer. In 1974, Professors F. Sherwood Rowland and Mario J. Molina recognised that when CFCs finally break apart in the atmosphere and release chlorine atoms they cause ozone depletion. Bromine atoms released by Halons have the same effect.

The ozone layer absorbs most of the harmful ultraviolet-B radiation from the sun. The ozone shield is thus essential to life as we know it. Depleting the ozone layer allows more UV-B to reach the earth.

In Malta ‘Ozone Day' is being marked with an activity organized by the Environment Protection Department at Freedom Square Valletta, on Thursday, 16 September 1999, starting at 9.00 a.m.