In 2014, we received the first good news about the ozone layer, that the ozone layer is finally healing. The Montreal Protocol’s Scientific Assessment Panel says that we can expect a near-complete ozone layer recovery by the middle of the 21st century. This is a feat that was achieved only through global efforts and cooperation.

The Montreal Protocol was adopted by all 198 UN Member countries on 15^th September 1987. It played a key role in the process of saving the ozone layer before it was too late. Such drastic and quick steps had to be taken because of the high amounts of chlorofluorocarbons (CFCs) released into the atmosphere during the 1980s and 90s.

In simple terms, the ozone layer acts as a sort of sunscreen, protecting the Earth by absorbing around 98% of harmful, cancer-causing UV rays of the Sun. It is located in the stratosphere, about 15-30 km above the Earth’s surface.

Ozone molecules consist of three oxygen molecules. It naturally goes through the cycle of being destroyed and reformed. But CFCs make it very difficult for ozone molecules to rejoin once it is broken apart. For example, one chlorine atom, which is CFCs’ main component, can destroy thousands of ozone molecules. Thus, ozone gets destroyed at a faster rate than it is created.

The damage done to the ozone layer due to these chemicals is commonly called ozone holes, although they aren’t holes – rather, they are areas where the ozone layer is extremely thin due to its depletion.

The Antarctic Ozone Hole is one of the most giant known ozone holes – it has been monitored since 1980 and is one of the longest-lasting. In 2020, the Antarctic hole grew and peaked at 24.8 million square kilometres. It finally closed in December 2020.

Earlier, it was only CFCs that were considered to be ozone-harming. But now, a range of substances called ozone-depleting substances come under the harmful category.

Hence, it has become the need of the hour to strictly regulate the number of CFCs released into the atmosphere. The Montreal Protocol is the main ozone-focused international treaty that aims to phase out ozone-depleting substances (ODS) production and consumption.

Similarly, the Kigali Amendment of the Montreal Protocol signed on October 15, 2016, has been put in place to reduce the production of hydrofluorocarbons (HFCs) and CFCs. Because of its worldwide participation, the Montreal Protocol encouraged huge investments in alternative technologies that would replace CFCs in commercial and industrial sectors.

This global effort resulted in the reduction of CFC usage – from over 800,000 metric tons in the 1980s to approximately 156 metric tons in 2014.

The swift implementation and the results seen due to the Montreal Protocol are proof that it is possible to reduce the human-induced negative impacts on the environment when nations choose to work together.