SINGAPORE – A huge hole that appeared in the Earth’s protective ozone layer above the Arctic in 2011 was the largest recorded in the northern hemisphere, triggering worries the event could occur again and be even worse, scientists have said in a report. The ozone layer high in the stratosphere acts like a giant shield against the sun’s ultraviolet radiation, which can cause skin cancers and cataracts.
Since the 1980s, scientists have recorded an ozone hole every summer above the Antarctic at the bottom of the globe.
Some years the holes have been so large that stretched to parts of South America, leading to worries about a surge in skin cancers. During extreme events, up to 70 per cent of the ozone layer can be destroyed, before it recovers months later.
A matching hole above the Arctic was always much smaller, until March this year when a combination of powerful wind patterns and intense cold high in the atmosphere created the right conditions for ozone-eating chlorine chemicals to damage the layer. – (Reuters)