March 10, 2014
Four New Ozone-Depleting Gases Discovered In Earth’s Atmosphere
Brett Smith for redOrbit.com - Your Universe Online
New research from a European team of scientists has identified four new artificial gases in the atmosphere that are depleting the ozone layer, according to a report published Sunday in the journal Nature Geoscience.
The report estimated that nearly 82,000 tons of three newly identified chlorofluorocarbons (CFCs) and one newly found hydrochlorofluorocarbon (HCFC) have been released into the atmosphere.
“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 study author Johannes Laube, a chemist at the University of East Anglia.
“CFCs are the main cause of the hole in the ozone layer over Antarctica,” Laube added. “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.”
The study team found the new gases by testing unpolluted air samples collected from Tasmania between 1978 and 2012. The results of these tests were compared to an analysis of air trapped in ice cores extracted from Greenland in 2008. The ice cores provided a hundred-year record of atmospheric conditions over Greenland.
The researchers found that all four of the newly identified gases were emitted into the atmosphere recently, and that two are building up considerably. Emission spikes of this degree haven't been seen for any other CFCs since regulations were in place during the 1990s. However, they are nowhere near peak CFC emissions of the 1980s, which came to around a million tons annually, according to the research team.
“The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer,” Laube said. “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,” he added.
The gases were found to have existed sooner in Greenland than Tasmania, suggesting they were created in the northern hemisphere – after which they were blown south. Laube said research planes could possibly discover the sources by capturing air samples around the world.
"While these newly discovered 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," Martyn Chipperfield, a professor of atmospheric chemistry at the University of Leeds, told Reuters.
"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," he said.
The ozone layer guards our planet from ultra-violet rays, which can trigger skin cancer and eye cataracts. The protective shield has been recovering after a phase-out of the chemicals under the UN's 1987 Montreal Protocol.