A new report in the journal Nature Geoscience has identified traces of four man-made gases in the atmosphere that are capable of destroying the ozone layer and exacerbating climate change. According to the scientists, at least two of the four are accumulating at rates that are cause for concern.
The Montreal Protocol, signed in 1987, was designed to save the ozone layer and prevent dangerous ultraviolet radiation from reaching people. While the ozone hole has reached near record size several times in recent years, NASA studies have found that these fluctuations were primarily due to natural meteorological conditions. Scientists recently said that the hole was stabilizing, but that it may take until 2070 to fully recover.
“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 team of researchers from Europe and Australia wrote in the journal Nature Geoscience. “The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer,” they said in an added statement.
Three of the gases are chlorofluorocarbons (CFCs), chemicals normally found in air-conditioning, refrigerators and aerosol spray cans, and banned under the Montreal Protocol. The fourth is a hydrochlorofluorocarbon (HCFC), a related group of compounds. The Montreal Protocol originally banned the 13 harmful CFCS and HCFCs known at the time, and in 2010 was extended to ban all CFCs. The researchers analyzed air samples from Tasmania collected since 1978 as well as snow samples from Greenland in making their discovery.
Hydrofluorocarbons (HFCs) are also used as a refrigerant and coolant. While they are non-ozone depleting, they can be up to a thousand times more potent of a greenhouse gas than carbon dioxide. In June the U.S. and China agreed to support phasing out HFCs, but certain developing countries like India have been resistant. If agreed upon, a reduction in HFCs could help avoid up to half a degree Celsius of human-caused warming by 2100.
“We don’t know where the new gases are being emitted from and this should be investigated,” lead researcher Dr. Johannes Laube told the BBC. “Possible sources include feedstock chemicals for insecticide production and solvents for cleaning electronic components.”
Professor Piers Forster from the University of Leeds told the BBC that the new research reminds us that ozone depletion is not yesterday’s story. “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.”
Like carbon dioxide and other greenhouse gases contributing to climate change, the new compounds discovered by the researchers take decades to break down into the atmosphere. So curtailing the cause of the problem before emissions rise higher will have an outsized impact down the line.