Geneva, Sept 17: The hole in the protective Ozone layer over the Antarctic, regarded as one of the world's major environmental challenges, has expanded more rapidly than in recent years, reaching the record level set three years ago, climate experts said on today. The World Meteorological Organisation (WMO) 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.

Last year's recovery had prompted some officials to claim that international efforts to control chemical-based pollutants which destroy the ozone layer were starting to have an impact.
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.

The hole, which is influenced by seasonal climatic conditions as well as pollution, normally reaches its peak in mid to late September and is regarded as a barometer of the overall state of the Ozone layer in the rest of the world.
The layer has been eroded by pollutants such as aerosol gases or refrigerants, although these substances are gradually being phased out under a 1987 UN treaty, the Montreal protocol.

"Complete recovery of the ozone layer will require continuing diligence with the enforcement of international agreements," WMO warned.

Bureau Report