Alarm over Earth’s protective shield: Ozone hole has grown LARGER than North America

Earth'S ozone hole has grown to a record size that is unprecedented in recent years, NASA and the US National Oceanic and Atmospheric Administration (NOAA) have said.

  

At a whopping 28.2 million square kilometres this makes it the fourth largest measured since 1991 - raising concerns as the ozone layer keeps the sun’s potentially deadly rays in check.

The ozone layer is a protective shield around our planet, keeping ultraviolet radiation that can cause cancer, cataracts and weaker immune system, at bay.
The larger hole will mean more harmful radiation hitting the Earth this year, especially in the southern hemisphere - areas like Australia, New Zealand and Falkland islands.
 

Detected in the 1980s, the hole was so alarming that the international community quickly agreed to ban the release of such chemicals, which were found in refrigerants and fire suppressants.
The ban has seen the hole steadily shrink, though it is not expected to fully recover until 2070.
And this year’s cold temperatures high up in the atmosphere have made the hole grow to record levels.
The hole’s size normally varies throughout the year, usually growing in August and September when there are more active chemicals in the atmosphere depleting the ozone layer for a few weeks.

"During September we typically see a rapid ozone decline, ending with about 95 percent depletion in that layer by October 1,” said Johnson.
"This year the depletion held on an extra two weeks resulting in nearly 100 percent depletion by October 15.”
The agencies say this was down to unusually cold temperature and weak dynamics in the Antarctic stratosphere this year.
"While the current ozone hole is larger than in recent years, the area occupied by this year's hole is consistent with our understanding of ozone depletion chemistry and consistent with colder than average weather conditions in Earth's stratosphere, which help drive ozone depletion," said Paul A. Newman, chief scientist for Earth Sciences at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Culled from www.express.co.uk