(From The Guardian)
A sharp and mysterious rise in emissions of a key ozone-destroying chemical has been detected by scientists, despite its production being banned around the world.
Unless the culprit is found and stopped, the recovery of the ozone layer, which protects life on Earth from damaging UV radiation, could be delayed by a decade. The source of the new emissions has been tracked to east Asia, but finding a more precise location requires further investigation.
CFC chemicals were used in making foams for furniture and buildings, in aerosols and as refrigerants. But they were banned under the global Montreal protocol after the discovery of the ozone hole over Antarctica in the 1980s. Since 2007, there has been essentially zero reported production of CFC-11, the second most damaging of all CFCs.
The rise in CFC-11 was revealed by Stephen Montzka, at the US National Oceanic and Atmospheric Administration (NOAA) in Colorado, and colleagues who monitor chemicals in the atmosphere. “I have been doing this for 27 years and this is the most surprising thing I’ve ever seen,” he said. “I was just shocked by it.”