By: By Eric Zerkel
Published: March 10,2014
After comparing present day air samples with ice core samples from Greenland and more than 30 years of air samples from Tasmania, researchers found that more than 74,000 metric tons of three chlorofluorocarbons (CFCs) and one hydrochlorofluorocarbon (HCFC) had been released into the atmosphere since the 1960s, reports the Wall Street Journal.
Both synthetic gases contribute to ozone depletion, but CFCs are considered the most damning to the earth's natural ultra-violet ray filter, the ozone layer.
"Our research has shown four gases that were not around in the atmosphere at all until the 1960s, which suggests they are man-made," the scientists said. "The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer."
Worse yet, two of the four newly discovered gases are still being released into the atmosphere, and scientists don't yet know the source.
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"We don't know where the new gases are being emitted from, and this should be investigated," the group of scientists told the AFP.
Traces of the gases were discovered earlier in the historical record in Greenland than in Tasmania, which helped scientists narrow down the source of the emissions to the northern hemisphere, reports Reuters.
"The further south we measured, the less there was, which means the gases are predominately being emitted in the northern hemisphere," atmospheric chemist Johannes Laube told the Wall Street Journal.
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The most troubling aspect of the news is that one of the gases still being released into the atmosphere is a CFC. CFCs, once found in many refrigerants and aerosols, were phased out of production starting in 1989 and later banned in 2010 after contributing greatly to a hole in the ozone layer over Antarctica, reports the AFP. According to Reuters, the concentration of one of the CFC's is increasing at a rapid pace.
While the presence of the four new gases is concerning, Laube said that the concentration of the gases shouldn't "cause concern at the moment" but that the discovery warranted an "investigation."
"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.
For more, access the scientists' full study on Nature Geoscience.
MORE: Alaskan Glaciers in Retreat
Reid Glacier (2003)
![Muir Glacier and Inlet (1895)](http://s.b.imwx.com/dru/2013/11/7404db24-bd4d-4438-bafa-7a3b905c1ecb_650x366.jpg)
In the 104 years between photographs, Reid
Glacier has retreated nearly 2 miles. The hillside in the foreground is
covered with dense vegetation, including both conifers and deciduous
trees. Vegetation covers much of the lower slopes on the opposite side
of the inlet. (USGS/Bruce Molnia)
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