Geneva, Aug. 23 (Reuters): The annual depletion of the earth’s protective ozone layer has begun over Antarctica and the hole is set to expand in coming weeks, the World Meteorological Organisation said today.
In its latest bulletin, the WMO said the size of the ozone hole over the Antarctic was “normal for this time of year”.
The depletion began as delegates prepared to discuss environmental issues in Johannesburg next week at the Earth Summit, officially the United Nations’ World Summit on Sustainable Development.
The ozone layer protects people from harmful radiation and many scientists blame its depletion on chemicals such as chloroflurocarbons (CFCs) and some crop fumigants.
The Geneva-based United Nations agency said a second region of very low ozone levels had appeared near the southern tip of South America and spread north over much of Argentina.
“As expected, the annually occurring ozone hole is again forming over Antarctica.
The ozone hole is still small, but will expand and deepen during the next four to six weeks,” WMO said.
“The low ozone observed over Argentina may not be entirely due to the ozone hole but have a meteorological component, although the progression of the low ozone region from the Antarctic perimeter northward suggests ozone loss has contributed,” it added.
WMO said earlier this month that as the sun rises over Antarctica, chemical ozone loss could be expected to occur with an intensity linked to weather conditions in the stratosphere, particularly in September and October.
Weather conditions would strongly influence the extent and persistence of the ozone hole.
Today, WMO said measurements of ozone over Buenos Aires were up to 20 per cent lower than the “pre-ozone hole norms” based on readings from 1964 to 1976.
Satellite measurements indicated that ozone values over the British island of South Georgia in the southern Atlantic Ocean were 35 per cent below the readings from that period, it added.