Ozone-depleting gases are naturally occurring elements that threaten to destroy the environment. When released into the atmosphere, they are dangerous to humans because they powerfully trap heat and remove protection against ultraviolet (UV) light that causes cancer in humans and animals and damages vegetation. A recently released study in England, published in Nature Geoscience, has determined that four such man-made gases are destroying earth’s stratospheric shield. It is uncertain what these gases are due to. They are being emitted despite an international United Nations treaty 27 years ago. The treaty, “the Montreal Protocol,” would have led to complete ban of such gases four years ago.
The gases that are continuing to be emitted are three new chlorofluorocarbons (CFC) and one new hydrochlorofluorocarbon (HCFC), however their source is unknown. The determination was found through new technology. This allowed scientists to glimpse the quality of air 100 years ago by creating a snapshot based on air samples in deeply compacted snow found in Greenland. That photo was used to compare to recent air samples (1978-2012) in an area unaffected by pollution: the remote Cape Grim in Tasmania.
Through the comparison, the researchers, led by Johannes Laube of the University of East Anglia in England, found that the four new gases did not exist until the 1960s, suggesting that they were created by humans.
CFC and HCFC, invented in the 1920s, are composed of carbon, chlorine, and fluorine, which release chlorine atoms that lead to ozone depletion in the atmosphere. For many years, they were used in refrigeration and in aerosol, but were prohibited in 1987, after a hole in the ozone layer was discovered between 15 and 30cm above Antarctica. Since that time, there has been considerable thinning of the layer, exposing the earth to harmful rays.
Ambiguity in the law and exceptions are to blame for ozone depletion due to the continued leakage of CFC and HCFC gases, despite the 27-year-old ban. These gases were due to be eliminated four years ago, and this new discovery means that, even if no new emissions were to be released, it will be additional decades before the existing substances break down.
Even though the amount of CFC emissions is greatly reduced from that in the 1980s, the existence of the gases is still a worry for scientists, environmentalists, and others. Most concerning is that they are being produced, and still accumulating, in contradiction to the intentions of the 1987 Protocol. This implies that vigilance is needed to ensure safety of the environment so that gas emission that leads to ozone depletion – whether accidental or unplanned – does not continue to occur.
Moreover, not knowing the exact source leads researchers to their next step of determining what is causing the gases to be emitted. There is speculation that it may be due to chemicals that produce insecticide and cleaning solvents for electronics. Some study results lead researchers to believe that the primary source of the gases is in industrial areas in the Northern Hemisphere.
What is most troubling about this new discovery is that no one knew – or spoke of – the continued leakage of gases that lead to ozone depletion and the assumption was that the ban 27 years ago was being adhered to. It is due to the aforementioned study that we have data, and the next step is investigative inquiry.
By Fern Remedi-Brown