A team of researchers from UEA have recently discovered the existence of four new man-made chemicals, all of which contribute significantly to the destruction of the ozone layer. Three chlorofluorocarbons (CFCs) and one hydrochlorofluorocarbon (HCFC) have recently been released into the atmosphere, despite the fact that laws aimed at reducing their usage have been in place for decades.
Lead researcher Dr Johannes Laube, of UEA’s School of Environmental Sciences, said in a press release by the university: “CFCs are the main cause of the hole in the ozone layer over Antarctica. Laws to reduce and phase out CFCs came into force in 1989, followed by a total ban in 2010. This has resulted in successfully reducing the production of many of these compounds on a global scale. However, legislation loopholes still allow some usage for exempted purposes.”
More than 74,000 tonnes of the gases have been emitted with no known source of origin. Laube suggested, “Possible sources include feedstock chemicals for insecticide production and solvents for cleaning electronic components.”
The scientists uncovered the new CFCs through comparing modern air samples with samples collected from polar firn snow—a type of ice comprised of years-old recrystallised snow. They also looked at air collected on the uncontaminated island of Tasmania between 1978 and 2010.
Emissions of the new CFCs have reportedly reached the highest levels recorded since control laws were introduced. However, they do not rival the emission rates seen in the 1980s, which peaked at roughly a million tonnes per year.
According to an article published by The Guardian, there were, until recently, 13 CFCs and HCFCs identified as destructive to the ozone. The Montreal Protocol—an international treaty aimed at ozone preservation—curbed the release of these known compounds. However, CFCs decay very slowly in the atmosphere, and Laube noted, “even if emissions were to stop immediately, [CFCs] will still be around for many decades to come.”
The full details of the findings made by Laube and his team can be found in an issue of the journal Nature Geoscience published Sunday March 9.