The unexplained discovery of new accumulations of ozone-depleting gases is ringing alarm bells
Remember the ozone hole? The signature environmental concern of the 1980s all but dropped from popular media attention after a total global ban on production of chlorofluorocarbon (CFC) gases came into force in 2010.
Researchers thought the giant ozone hole over Antarctica was on its way to being completely eliminated by 2065, but that assessment is now being called into question with the discovery of accumulations of four gases by scientists at the University of East Anglia (UEA). Three of the gases are CFCs and one is a hydrochlorofluorocarbon (HCFC), which can also damage ozone.
There is a strong international treaty – the Montreal Protocol – that regulates these ozone-depleting substances. But there are loopholes in the rules that allow for their use under certain circumstances, which, some say, may be linked to the new ozone-attacking gases.
Scientists are concerned. “The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer,” says Dr Johannes Laube, from UEA’s school of environmental sciences. Before this recent discovery, seven types of CFC and six types of HCFC had been shown to contribute to stratospheric ozone destruction.
The UEA’s research shows that the new gases have only been in the atmosphere since the 1960s – which indicates that they are manmade.
So, where are they coming from? “We don’t know where the new gases are being emitted and this should be investigated,” Dr Laube says. “Possible sources include feedstock chemicals for insecticide production and solvents for cleaning electronic components.”
When potentially ozone-depleting substances are used in non-dispersive processes such as feedstock and chemical production, they are technically allowed under the Montreal Protocol.
The responsibility of tracking ozone-depleting substances around the world lies with government and some university-based researchers. Support continues in this community for the Montreal Protocol’s oversight function.
“One of the protocol’s main strengths is the way in which it is regularly adjusted and amended,” says Steve Montzka, an earth systems research lab scientist at the US National Oceanic and Atmospheric Administration, who is involved with measuring these trace gases.
Demonstrating this strength, environmental NGOs were successful in lobbying for the protocol to also regulate the hydrofluorocarbons (HFCs) that replaced the CFCs and HCFCs that the protocol had phased out. HFCs are a powerful greenhouse gas, 1,000 times more so than carbon dioxide.
As HFCs don’t contain chlorine they don’t directly deplete the ozone layer, though it’s been established that small amounts of CFCs and other chemicals used for feedstocks in the production of HFCs are ozone-depleting substances.
While the science is complex, and the scale of the potential problem and its rate of development unclear, experts agree that more research is required.atmosphere CFC environmental regulation manmade Montreal Protocol ozone pollution