A ‘hole’ in the ozone layer over Antarctica has shrunk to its smallest size on record, Nasa has announced.
The ozone layer is a part of the Earth’s atmosphere which protects the Earth from the sun’s dangerous cancer-causing ultraviolet radiation.
In the 1970s it was first discovered that chemicals called CFCs used in refrigerators, aerosol sprays and engine coolants were thinning the ozone over the South Pole.
This year, the huge wound in our planet’s protective sun-shield shrank to 3.9 million square miles.
‘It’s great news for ozone in the Southern Hemisphere,” said Paul Newman, chief scientist for Earth Sciences at Nasa’s Goddard Space Flight Center.
‘But it’s important to recognize that what we’re seeing this year is due to warmer stratospheric temperatures.
‘It’s not a sign that atmospheric ozone is suddenly on a fast track to recovery.’
The ozone layer sits seven to 25 miles above Earth’s surface.
It shields everything on this planet from potentially harmful ultraviolet radiation that can cause cataracts, cancer and immune system problems.
The hole is small because unusually warm weather limited the depletion of ozone.
Similar weather patterns in 1988 and 2002 also resulted in much smaller holes than usual.
‘It’s a rare event that we’re still trying to understand,’ said Strahan.
‘If the warming hadn’t happened, we’d likely be looking at a much more typical ozone hole.’
Antarctic ozone slowly decreased in the 1970s, with large seasonal ozone deficits appearing in the early 1980s.
But it’s now shrinking slowly and is expected to recover to its 1980 level in about 2070.