March 9, 2014

expert reaction to new study on ozone-depleting gases

Small amounts of four newly detected ozone-depleting substances started to emerge in the atmosphere in the 1960s, according to a study published Nature Geoscience. 

Prof William Collins, Prof of Meteorology at the University of Reading, said:

“Although these new emissions are small (contributing a fraction of a percent of the total emissions of ozone depleting substances), for the Montreal protocol to continue to be successful it is necessary to understand whether it is being strictly complied with. This study provides useful new information on policing the Montreal protocol, tracing sources of new CFCs that are possibly arising as the by-products of manufacturing other chemicals.”

Prof Martyn Chipperfield, Professor of Atmospheric Chemistry at the University of Leeds, said:            

“While these newly discovered that gases can, in theory, cause some damage to the ozone layer, their combined abundance is over 500 times smaller than that of the main ozone-destroying compounds in the 1990s, which we know have been effectively controlled by the Montreal Protocol.  Therefore, these new observations do not present concern at the moment, although the fact that these gases are in the atmosphere and some are increasing needs investigation.  Overall the Montreal Protocol is still on track to remove the main ozone-destroying substances from the atmosphere and safeguard the ozone layer.”

Prof Piers Forster, Professor of Climate Change at the University of Leeds, said:

“This paper highlights that ozone depletion is not yet yesterday’s story.  The Montreal protocol – the most successful international environmental legislation in history – phased out ozone-depleting substances from 1987 and the ozone layer is still set to recover by 2050. 

“The protocol by chance also had huge benefit for future climate as it phased out CFCs – which are very long lived and potent greenhouse gases.  The concentrations found in this study are tiny.  Nevertheless, this paper reminds us we need to be vigilant and continually monitor the atmosphere for even small amounts of these gases creeping up, either through accidental or unplanned emissions. 

“Of the four species identified CFC-113a seems the most worrying as there is a very small but growing emission source somewhere, maybe from agricultural insecticides.  We should find it and take it out of production.”

‘Newly detected ozone-depleting substances in the atmosphere’ by Johannes Laube et al published in Nature Geoscience on Sunday 9 March 2014.