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.
Would create new distribution, content creation giant, if approved by regulators
Waves of cyberattacks disrupt services for many East Coast US Internet users
Critics slam company after claims it allowed NSA to scan all users’ emails
Shenzhou-11 to take 2 astronauts into space, dock with orbiting space lab Tiangong-2 within 2 days
A German politician has said Facebook should pay for failing to remove online hate comment
For the first time in over 120 years, a design patent case will be heard by the US supreme court.
Toyota is usually associated with cars, but it has been investing millions in robotics and Kirobo is its first commercial foray into the sector.
A joint Mongolian-Japanese expedition found the giant print, which measures 106 centimetres (42 inches) long and 77 centimetres wide.
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.