Scientists are searching for the origin of four man-made gases that damage ozone and have somehow infiltrated the atmosphere.
Published in the journal Nature Geoscience, recent findings revealed new gases similar to the chlorofluorocarbons invented in the 1920s and banned in the 1980s.
"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 lead researcher Dr. Johannes Laube, as reported by BBC News.
"The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer," he said.
Used in refrigeration and as aerosol propellants, CFC gases contributed to a "hole" in the ozone layer over Antarctica. Officials worldwide worked together to ban their production, introducing the Montreal Protocol in 1987 to protect the ozone layer, which keeps harmful UV rays from the Earth.
Two of the four new gases are especially building up in the atmosphere, and researchers estimate that some 74,000 tons of the four gases have been released altogether. Three of them are CFCs, while one is a hydrochlorofluorocarbon gas.
The concentration of these gases is relatively small, and they're aren't yet a concern; however, their source should be found before the situation gets worse.
"We don't know where the new gases are being emitted from and this should be investigated," Laube said, as quoted by BBC. "Possible sources include feedstock chemicals for insecticide production and solvents for cleaning electronic components."
The gases were discovered when scientists analyzed "polar firm" in Greenland, packed snow that can help scientists gauge the atmosphere for the last 100 years.
Even if the source of the gases is discovered and their production is stopped, the CFCs will remain in the atmosphere for a long time.
"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," Laube said.
See Now: OnePlus 6: How Different Will It Be From OnePlus 5?