Four gases contributing to the destruction of the ozone layer were identified in the atmosphere. All four of them have been released into the atmosphere recently.
Scientists at the University of East Anglia made the discovery by comparing today's air samples with air trapped in polar firn snow in Greenland sampled in 2008, and also looking at air collected between 1978 and 2012 in unpolluted Tasmania. Research has shown four gases that were not around in the atmosphere at all until the 1960s which suggests they are man-made.
So far, seven types of CFC and six types of HCFC have been shown to contribute to stratospheric ozone destruction. More than 74,000 tonnes of three new chlorofluorocarbons (CFCs) and one new hydrochlorofluorocarbon (HCFC) have been released into the atmosphere. Since 1990s, emission increases of this scale have not been seen for any other CFCs. This is still far from peak CFC emissions of the 1980s which reached around a million tonnes a year. CFCs are the main cause of the hole in the ozone layer over Antarctica.
"The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer. 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. What's more, the three CFCs are being destroyed very slowly in the atmosphere - so even if emissions were to stop immediately, they will still be around for many decades to come." Lead researcher Dr Johannes Laube from UEA's School of Environmental Sciences.
Relative amount of effective stratospheric chlorine and atmospheric abundance graphs. (Source: The Ozone Hole)
CFCs have a lifetime in the atmosphere of about 20 to 100 years, and consequently one free chlorine atom from a CFC molecule can do a lot of damage, destroying ozone molecules for a long time. Newly reported emissions are clearly contrary to the intentions behind the Montreal Protocol, and raise questions about the sources of these gases. Laws to reduce and phase out CFCs came into force in 1989, followed by a total ban in 2010. Many of these compounds were successfully reduced on a global scale, however, some usage for exempted purposes is still allowed.
In 1978 The Montreal Protocol was adopted as a framework for international cooperation regarding CFC control on the basis of the Vienna Convention for the Protection of the Ozone Layer. (Source: UNEP)
- "Newly detected ozone depleting substances in the atmosphere" was published in the journal Nature Geoscience on March 9, 2014.
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