Most people think that the ozone layer has recovered since CFCs and other similar gasses were banned back in 1987. However, a team of scientists have discovered alarming levels of four new artificial gasses that could harm the ozone layer.
The researchers found four new gasses including a hydrochloroflourocarbon (HCFC) and three types of chloroflourocarbons (CFC) in the atmosphere. The team also discovered that over 74,000 tonnes of these harmful gasses are now eating away at the ozone layer.
The research team made the discovery after analyzing air samples found in polar firn snow and comparing them from samples taken from the atmosphere. Since air trapped in polar firn snow can be used to create a history of atmospheric compositions, the scientists were able to determine changes in gas levels. To complete the study, the scientists also analyzed older air samples that were taken between 1978 and 2012. The older air samples were gathered from Tasmania where air pollution levels are very low.
"Our research has shown four gases that were not around in the atmosphere at all until the 1960s which suggests they are man-made," said Johannes Laube, a chemist from the University of East Anglia's School of Environmental Studies. Laube is also the lead author of the study.
Laube and his colleagues submitted their findings to the online journal Nature Geoscience. The four gasses that the scientists detected were released recently. Moreover, two of the new gasses have reached worrying levels and the concentrations of these two gasses continue to rise.
"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," said Laube. "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."
While the current levels of these harmful gasses are a cause for concern, the levels are still relatively small especially when compared to the CFC levels in the atmosphere back in the 1980's. Before CFCs and other similar gasses were banned, CFC levels reached record highs of close to one million tonnes per year.
"The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer," added Laube. "We don't know where the new gases are being emitted from and this should be investigated. Possible sources include feedstock chemicals for insecticide production and solvents for cleaning electronic components."
