Date
14 December 2017
The ozone hole over Antarctica has been shrinking but it's still the size of the North American continent. Photo: NASA
The ozone hole over Antarctica has been shrinking but it's still the size of the North American continent. Photo: NASA

Antarctic ozone hole shrinks but still as big as North America

Global efforts to heal the ozone layer above the antarctic are paying off but the hole is still nearly as large as the North American continent, The Independent reported Monday.

At its widest point, the hole is about 24.1 million square kilometres, nearly unchanged from 2013, the report said, citing the National Aeronautics and Space Administration.

However, it is far smaller than the largest single-day ozone hole ever recorded by a satellite at 29.9 million square kilometres in September 2000.

The phenomenon was worst between 1998 and 2006 and ozone levels in the hole area seem to be gradually recovering.

The hole forms and expands over the antarctic during the Southern Hemisphere spring between August and September.

The depletion of the ozone layer became a cause of international concern because it is needed to shield life on Earth from potentially harmful ultraviolet radiation that can cause skin cancer and damage plants, the report said.

The Montreal Protocol of 1987 aimed to protect the ozone layer by reducing production of substances responsible for depleting it, such as chlorine and bromine, found in chlorofluorocarbons and halons.

In 2014, the level of these substances had fallen by about 9 per cent from the record maximum in 2000.

Scientists are working to determine whether the reduction in the hole’s size is a result of the reduction in chlorine or temperature increases, which would also decrease its size.

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