World Bulletin/News Desk
The hole in the ozone layer, the earth's protective shield against ultraviolet rays, is expected to be smaller this year over the Antarctic than last, showing how a ban on harmful substances has stopped its depletion, the United Nations said on Friday.
But the hole is probably larger than in 2010 and a complete recovery is still a long way off.
The signing of the Montreal Protocol 25 years ago to phase out chemicals that deplete the ozone layer has helped prevent millions of cases of skin cancer and eye cataracts as well as harmful effects on the environment, the U.N. weather agency said.
"The temperature conditions and the extent of polar stratospheric clouds so far this year indicate that the degree of ozone loss will be smaller than in 2011 but probably somewhat larger than in 2010," the World Meteorological Organization (WMO) said in a statement.
The Antarctic ozone hole, which currently measures 19 million square kilometres, most likely would be smaller this year than in the record year of 2006, it said. The annual occurrence typically reaches its maximum surface area during late September and maximum depth in early October.
But the banned chlorofluorocarbons (CFCs), once used in refrigerators and spray cans, have a long lifetime in the atmosphere and it will take several decades before their concentrations are back to pre-1980 levels, the WMO said.
The Montreal protocol has been a "great success", U.N. weather agency expert Geir Braathen told a news briefing.
"This has prevented a major environmental disaster and globally ozone depletion has levelled off. We haven't really seen any kind of unequivocal ozone recovery yet," he said.
"Ozone depletion has stopped, levelled off," Braathen said.
In the Arctic stratosphere, there was record ozone loss in spring of 2011, but it has returned to more normal conditions this year, he said.
Current conditions may ‘commit Earth to an eventual total warming of 5 degrees Celsius’ in few thousand years, author says
Cyber-attack in 2014 likely the largest data breach in history
Photographs, videos, polls, quoted tweets no longer count toward 140-character limit
2.5 million phones recalled days before Apple introduces iPhone 7
Mark Zuckerberg has vowed to continue effort to provide satellite for Africa
3.7-billion-year-old rock suggests life began soon after Earth’s formation
Facebook will target advertising to Whatsapp users but will steer clear of third party advertising content
The global seed giant Monsanto is pulling its application to introduce GMO cotton seed after a row with the Indian government, which is demanding the company share its technology with local seed companies.
Proxima b could be visited by spacecraft within next 100 years
According to Space X, the rocket “will be subject to extreme velocities and re-entry heating,” and is part of an ongoing effort to reuse rocket parts
Flaming blue fire vortexes could be used to clean up oil spills at sea
$4.8bn Ethiopian Grand Renaissance Dam prompting fears in Cairo that water could be cut off from downstream Nile nations
Israeli military concerned game could lead to locations and images of military bases being leaked
AG600 developed for use in emergency operations has max cruising speed of 500 km per hour, max flight range of 4,500 km
Vast quantities of rare gas hint at Earth’s past, could power planet’s future
Global temperatures at record highs; Arctic sea ice levels at record lows