Photograph courtesy of NASA
Scientists have found three types of previously undetected chlorofluorocarbons (CFCs) and one hydrochlorofluorocarbon (HCFC) in the atmosphere depleting the ozone layer, despite bans on their use.
In a study published in Nature Geoscience, researchers from the University of East Anglia led by Johannes Laube detected CFC-112, CFC-112a, CFC 113a and HCFC-133a in the atmosphere by analysing air samples from Tasmania in Australia, and air trapped in snow samples from Greenland.
The team determined that the gases were being emitted by the northern hemisphere, but they could not determine by which country, and most worryingly their emissions were increasing fast.
All of these chemicals are banned under the 2010 Montreal Protocol, but the researchers blame their use on legal loopholes in the regulations, where companies can apply for exemptions. Details about the legal exemptions given are sparse, and it is impossible to tell whether the rise is from exempted or illegal emissions.
CFCs and HCFCs were used as propellants and refrigerants, but their use has been internationally restricted or banned since the 1980s due to their release of ozone-depleting chlorine atoms in the atmosphere when broken down by ultraviolet light.
