Rio Declaration
Kyoto Protocol
Net Zero Pledges
I always wonder if these myriad conferences and agreements on climate have ever had any real impact on the world. Most climate conferences seem to be about making the right noises and then coming back next year to do more of the same!
However, while there is skepticism about the real impact of these conferences and agreements, there is one area in which collective action has yielded the desired results. The “hole” in the Ozone layer over Antarctica is now shrinking and this is attributed directly to the results of the Montreal Protocol of 1987.
Ozone Depletion: observed in the 1970s, there was a depletion of ~4% in the total amount of Ozone in the Earth’s atmosphere.
The Antarctic Ozone Hole: Discovered in 1980s, it is not exactly a hole, but rather a reduction in the amount of ozone in different regions of the atmosphere over Antarctica. The reduction is not uniform. Similar “holes”, but of much smaller size have also been observed in the Arctic and Tibet.
Chief Causes: Increased amount of chemicals emissions – chlorofluorocarbons (CFCs) present in refrigerants. These compounds when released, eventually break down the atmospheric Ozone into Oxygen.
Impact of Ozone Depletion: The Ozone layer prevents the harmful Ultra-violet rays from entering the earth’s atmosphere. With its depletion, it would lead to increased incidences of skin cancer, sunburns, cataracts and blindness in humans, increased temperatures globally, reduced crop yields etc.
Montreal Protocol, 1987: required countries to stop producing substances that damage the ozone layer, such as CFCs. The Montreal Protocol happens to be the only Treaty ratified by all UN members!
Impact of the Montreal Protocol: Post the ban on CFCs production in accordance with the Montreal Protocol from 1989 onwards, there has been a steady change in the atmospheric ozone. The depletion stopped in mid-1990s and the levels have been recovering. Currently, the hole in the Ozone layer has been the smallest since its discovery in 1980s. And as per current projections, the Ozone Layer is expected to completely regenerate by 2045! Truly, a remarkable success case.
As per UNEP, this has also helped in avoiding 0.5C of global warming by 2050!
Other Causes of Changes: There are seasonal changes to the amount of Ozone in the atmosphere. The depletion is greatest during spring and lowest in winter (when there is hardly any light) Major volcanic eruptions can also cause change in the composition. E.g., the Hunga Tonga-Hunga Ha’apai volcanic eruption of 2022 could have reversed the decline in the growth.
The Challenge
It took 4 decades for the damage to take place and another 7 decades+ to reverse it. Hope that we have not reached the irreversible stage in other areas!
However, there is one more challenge – the deniers. Every claim is denied backed by counter-research which seems equally credible. Whether the ozone layer is depleting, or it is caused by CFCs, or if ozone depletion does any damage – all of these have been disputed subjects by both scientists and the lobbyists.
A Case of Optimism
The reversal of the Ozone depletion through collective action does present a case of hope for the larger issue of Climate Change as well. While it took 4 decades for the damage to be noticed, its reversal is taking much longer. Just showing the scale of the task at hand. But at least, we have an example of how to yield the right result - Identifying the source and then collectively taking the corrective action to prevent permanent damage!
P.S. Unintentionally this post is getting published on the day Google is celebrating the birthday of Mario Molina, who discovered the harmful effects of CFCs on the Ozone layer, with a doodle.
Links:
- Global Climate Agreements: CFR
- Monitoring the Ozone Layer: Atmosphere
Previously on Learn N Blog: The Global Methane Pledge
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