The ozone layer is healing


A recent United Nations report brings us the news that the ozone hole is progressively disappearing, and that “ozone levels over most of the globe should recover to 1980 levels by 2050.” But our atmosphere is still under attack and needs consistent action to be protected.


Environmental news is rarely good, but it can still happen. On September 10, the World Meteorological Organisation and the United Nations Environment Programme announced that the ozone layer is healing: its hole has started to reduce. Their joint report, Assessment for Decision-Makers: Scientific Assessment of Ozone Depletion: 2014, concludes that “actions taken under the Montreal Protocol have led to decreases in the atmospheric abundance of controlled ozone-depleting substances (ODSs), and are enabling the return of the ozone layer toward 1980 levels.”

The efficiency of an international treaty

The Montreal Protocol is an international treaty signed in 1987 with entry into force in 1989. It has since been ratified by 197 states. When the treaty was signed, the ozone depletion phenomenon and the ozone hole had just been discovered, through a paper Joe Farman, Brian Gardiner and Jonathan Shanklin published in Nature in 1985. The Montreal Protocol thus aims at ‘protecting the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion’, such as chlorofluorocarbons (CFC), which have been progressively banned, explains Wikipedia. In 1987, Kofi Annan was already saying that the Montreal Protocol was “perhaps the single most successful international agreement », and today his words are truer than ever. Without it, the level of ozone-depleting substances could have multiplied tenfold by 2050. It is also estimated that, by 2030, two million cases of skin cancer will be avoided each year thanks to the treaty. “If nations continue to follow the guidelines of the Montreal Protocol, ozone levels over most of the globe should recover to 1980 levels by 2050. The ozone hole over the South Pole will take longer to recover, ending by 2070,”states the UNEP/WMO report. These findings are good news because they show that, to a certain extent, environmental damage is not irreversible and that it is always possible to curb and even to reverse the tendency. Political will and consistent action are of course essential, but change really can happen.

The ongoing challenge of climate change

That said, the report is no excuse for us to rest on our laurels. For starters, although the ozone layer is recovering, it is still being attacked by substances which are being produced in increasing quantities, such as carbon tetrachloride (even though it has been banned by the Montreal Protocol) or nitrogen dioxide (N02, which was not included in the list). But even more worrying is the fact that hydrofluorocarbons (HCFC), the substances that have been massively used to replace ozone-depleting ones, are very powerful greenhouse gases. In a way, it is as if the plague had been traded for cholera: less attacks on the ozone layer, but more impact on global warming and climate change. And emissions of these gases are increasing at a rate of 7% every year, according to the study.

The report is thus also a reminder that we must pursue and intensify our efforts to curb climate change. International cooperation has been shown to be an extremely efficient way to tackle environmental problems, which by their very nature concern the entire planet. May the example of the Montreal Protocol and its good results encourage us to make the right decisions to foster change.

Photo © oksix