If the source of these emissions can be identified and mitigated soon, the damage to the ozone layer should be minor.
If not, then it will take substantially longer than anticipated for the ozone layer to recover. Another possible explanation, that a lot of old buildings using CFC-11-based ventilation systems were demolished at the same time, was also ruled out, as it didn't plausibly fit the data, according to the team. 'The decline in CFC-11 is the graph that we all show in our atmospheric chemistry lectures to illustrate the effectiveness of the ban on CFCs.
The US National Oceanic and Atmospheric Administration (NOAA) in Colorado has alarmed the global community with their discovery of increased emissions of an ozone-depleting chemical, whose production was banned worldwide almost ten years ago.
If rogue production continues, it might just hold back the fragile recovery of Earth's vital ozone shield, despite years of success. This was partly because nations had all agreed to ban or phase out CFCs, which are short for "chlorofluorocarbons" but are simply called "ozone-depleting substances", due to an global treaty back in the 1980s called the Montreal Protocol. The researchers have said they would need more measurements to figure the exact location of the source and take necessary action.
CFC-11, used primarily for foams, can lasts up to 50 years in the atmosphere once it's released.
The researchers found that emissions of CFC-11 were between 2014 and 2016 up by a quarter from the average between 2002 and 2012.
Emissions of one of the chemicals most responsible for the Antarctic ozone hole are on the rise, despite an worldwide treaty that required an end to its production in 2010, a new study by researchers at NOAA and their colleagues shows. They found that the difference in CFC-11 concentrations between the northern and southern hemispheres has been increasing, which points to a northern hemisphere source.
The Montreal Protocol has been effective in reducing ozone-depleting gases in the atmosphere because all countries in the world agreed to legally binding controls on the production of most human-produced gases known to destroy ozone.
Keith Weller, a spokesman for the United Nations Environment Program, which helps implement the protocol, said the findings would be presented to the parties to the agreement for review. "They should tell the industries that's not going to work". If not, our ozone layer's fragile recovery could be under threat.
"This evidence strongly suggests increased CFC-11 emissions from eastern Asia after 2012".
But there a growing scientific doubts about the progress of healing in the ozone hole.