Just when you think the great ozone layer debate is over, more not-so-shocking findings make their way to the top of the pile.
New research published in the journal Nature Geoscience, led by the University of Bristol and the National Oceanic and Atmospheric Administration (NOAA), has revealed that global emissions of chlorofluorocarbons (CFCs) are on the rise – again. And climate activists across the world are hardly surprised.
CFCs are chemicals that are known to destroy the Earth’s protective ozone layer and were once widely used in the manufacture of hundreds of products including aerosol sprays, refrigerants, packing materials and blowing agents. The production of CFCs for such uses was banned under the Montreal Protocol in 2010, which aimed to protect the ozone layer, but allowed for exceptions for the production of other ozone-friendly alternatives to CFCs.
The research found that the rise in emissions was due to the production of CFCs during the manufacture of these alternatives. The study focused on five CFCs with few, or no, known current uses—CFC-13, CFC-112a, CFC-113a, CFC-114a, and CFC-115. Although the emissions from these CFCs do not currently threaten ozone recovery, they still have a significant impact on the climate, as they are potent greenhouse gases.
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The team determined that for three CFCs they studied – CFC-113a, CFC-114a, and CFC-115 – the increased emissions may be partly due to their use in the production of two common hydrofluorocarbons (HFCs) used primarily in refrigeration and air conditioning. However, the drivers behind the increasing emissions of the other two CFCs, CFC-13 and CFC-112a, are less certain.
CFCs are well-studied fluorocarbons. They can have a significant impact on the environment. Why? Because they are powerful greenhouse gases that trap heat in the atmosphere and contribute to global warming. Findings show that they can linger in the atmosphere for anywhere from 52-640 years, causing long-lasting damage to the environment.
Interestingly, the emissions of CFCs are also known to alter weather patterns, leading to an increase in extreme weather events such as floods, droughts, and heat waves, which ultimately contribute to climate change by raising the Earth’s temperature.
But CFCs are just one of the many troubling chemicals known to cause ozone depletion. Other banned chemicals include hydrochlorofluorocarbons (HCFCs), carbon tetrachloride and hydrobromofluorocarbons (HBFCs), to name a few. HBFCs, which were once commonly found in fire extinguishing agents, were phased out in 1996. But HCFCs are planned to be completely phased out by 2030, according to the Montreal Protocol.
HCFCs are harmful chemicals that were developed as a replacement for CFCs. However, they still have a negative impact on the ozone layer, according to researchers. The complete phase-out is scheduled for 2030 in developed countries and 2040 in developing countries. And during this time, the use of HCFCs will gradually be reduced each year. But some essential uses in certain industries or critical applications in certain countries are exempted from the phase-out.
What is the Montreal Protocol?
The Montreal Protocol, signed in 1987, was a bold move by the global community to address the catastrophic issue of ozone depletion caused by CFCs. The international agreement has been successful in reducing CFC emissions and allowing the ozone layer to recover and is considered a landmark environmental agreement, having been ratified by almost all countries in the world.
But now researchers are calling for a closer look into the effectiveness of the protocol, given how rapidly the world is changing.
Lead author Dr Luke Western, a Research Fellow at the University of Bristol and researcher at the NOAA’s Global Monitoring Laboratory (GML), said that “combined, their [CFC] emissions are equal to the CO2 emissions in 2020 for a smaller developed country like Switzerland. That’s equivalent to about one per cent of the total greenhouse gas emissions in the United States.”
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Although the team found rising global emissions, they were not able to identify particular locations. “Given the continued rise of these chemicals in the atmosphere, perhaps it is time to think about sharpening the Montreal Protocol a bit more,” said study co-author Dr Johannes Laube, from the Institute of Energy and Climate Research (IEK) at Forschungszentrum Jülich.
According to the researchers, if emissions of these five CFCs continue to rise, their impact may negate some of the benefits gained under the Montreal Protocol. The study noted that these emissions might be reduced or avoided by reducing leakages associated with HFC production and by properly destroying any co-produced CFCs.
“The key takeaway is that the production process for some of the CFC-replacement chemicals may not be entirely ozone-friendly, even if the replacement chemicals themselves are,” said Dr Western.