Ozone hole at record size
2003-09-17 13:12
Geneva - The hole in the protective ozone layer over the Antarctic has expanded more rapidly than in recent years and has reached the record level set three years ago, the World Meteorological Organisation said on Wednesday.
MO said in a statement that the 28-million-square-kilometre hole was in "stark contrast" to last year, when it had shrunk to its smallest level in more than a decade and split in two.
"It cannot be predicted with certainty whether the ozone hole will continue to grow during the next few weeks," WMO said.
The hole, which is influenced by climatic conditions as well as pollution, normally reaches its peak in mid- to late-September.
The ozone layer has been eroded by chemical-based pollutants used such as aerosol gases or refrigerants, although these substances are gradually being phased out under a 1987 UN treaty, the Montreal Protocol.
The layer of ozone gas in the earth's upper atmosphere filters harmful Ultra-Violet (UV) rays from the sun, and health officials have warned that excessive exposure to UV can cause skin cancer and other ailments, as well as destroy plant life.
In July Nasa said that satellite images had signalled that ozone depletion could be stabilising.