Emissions of ozone-depleting substances cause thinning of the protective ozone layer in the stratosphere. As a result of measures taken in Sweden and other countries, the negative impacts of ozone-depleting substances have already begun to decline.
If human production and use of ozone-depleting substances ceases, the ozone layer may recover over time. The hole in the ozone layer can be “mended” by a variety of measures and actions. But it will take time; the ozone layer is estimated to be fully recovered by the end of the century.
Oxides of chlorine, bromine and nitrogen cause chemical breakdown of the ozone, thus contributing to the “hole” in the ozone layer between 10 and 50 kilometres above the earth's surface.
The total thickness of the ozone layer at sea-level pressure and at 0°C would be between 2 and 5 millimetres. Thinning of the layer allows greater amounts of hazardous ultraviolet radiation to reach the ground. Ultraviolet-B radiation can split molecules apart and would cause serious damage to the health of plants, animals and humans if it were not absorbed by the ozone layer.
Reduction of emissions
Sweden's emissions of ozone-depleting substances have been reduced substantially since the end of the 1980s. The biggest emission source in Sweden today is leakage from products in which these substances are used as refrigerants and insulators.