Nations unite to plug the ozone hole

The hole in the ozone layer that spelled immense danger for the entire mankind is on its way to heal, a feat accomplished by a rare combined global effort when no country backed out or raised objections.

In a rare piece of good news on the environment, a UN-backed report has confirmed that the once-damaged ozone layer is slowly but noticeably healing and the process would completely mend the hole over Antarctica in about 43 years. While the hole over Antarctica which is the largest should be mended by 2063, the ones over the rest of the world may go back to 1980-level by 2040 itself, the report has predicted.

The world can collectively pat its back for this rare victory as this feat is a result of collaborative global efforts of eliminating some harmful chemicals which were responsible for the ozone hole. Let us have a closer look at what it means, why should we care and how it impacts mankind as a whole.

Why should we care about the ozone layer?

The ozone layer is part of the stratosphere that lies 10-50 km above the surface of the Earth. Ozone plays a huge role in Earth's existence by forming a protective layer over it. Ozone absorbs most of the sun's ultraviolet radiation and protects life on Earth. Without ozone, the sun's intense UV radiation would sterilize the Earth's surface.

In the 1980s, scientists found a worrying drop in the ozone layer in the stratosphere in the Antarctic. Two scientists, Mario Molina and Sherwood Rowland, argued in 1974 that chlorofluorocarbons (CFCs), widely used in refrigeration and in hairspray and other aerosols, are depleting the ozone layer. The two researchers later won the 1995 Nobel Prize in chemistry for their research.

According to the United Nations, if the ozone layer was left to deplete without any efforts, it would have increased tenfold by 2050 compared to the current levels. This increase would have resulted in millions of additional cases of melanoma, other cancers and eye cataracts. It has been estimated, for example, that the depletion is saving an estimated two million people each year by 2030 from skin cancer.

O3 did what no one else could: Brought the world together

As the researches and studies put forth the many implications and dangers that came with the depleting ozone layer, in a rather rare united front the world sat up and decided to act.

Ozone did what nothing or no one else had ever done in the past: It brought together all 198 UN member states who came together and signed the Montreal Protocol. The protocol formalised the mission to protect and repair the ozone layer by rapidly reducing the volume of ozone depleting gases being released into the atmosphere. Till date, it remains the only environment treaty to have all the member countries on board. While

As the world woke up to the dangers of depleting ozone layer, efforts to phase out the harmful chlorofluorocarbons started and the CFCs declined from over 8,00,000 tonne in 1989 to 156 tonne in 2014. The use of other ozone depleting gases has been reduced significantly and work is under way to go further. The Montreal Protocol maps the total phase-out of all ozone depleting gases by 2047.

O3 got worse before it got better

In 2022, scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA), reported that the ozone hole is continuing to shrink and reported that between 7 September and 13 October 2022, the hole above Antarctica spanned an average area of 23.2 million square kilometres. This was well below the average recorded in 2006 when the hole size was 27.5 million square kilometres.

However, the ozone hole did have the scientists' and experts' hearts racing in the initial years when the news almost always marked a worsening trend.

In 1987, the scientists had found that the hole over Antarctica had gone even bigger and by 1989 a thinned area was also detected in the ozone layer over the Arctic. Keeping the growing hole in mind, the Montreal Protocol was strengthened in 1990 to end production of CFCs in industrialised countries by the end of 2000. Rich countries also agree to help poorer countries meet the costs of complying with the Protocol. India joined the accord in 1992.

The bad news, however, continued to spell immense danger for the world. In September 2006, the biggest ever hole was seen in the ozone layer over the Antarctic and things were getting scarier and 'bigger'. In September 2007, a historic accord was reached in Montreal to advance by 10 years to 2030 the elimination of HCFCs by developing states. It was only in 2016 that US and UK researchers confirmed that the hole over Antarctica was finally shrinking.

How long before the hole is completely fixed?

If the Montreal Protocol is fully implemented the ozone layer is projected to recover by 2050. The United Nations Environment Programme (UNEP) says: "Without this treaty, ozone depletion would have increased ten-fold by 2050 compared to current levels."

This huge reduction in the release of ozone depleting substances is also helping to reduce global temperature rise by 0.5°C by 2100, according to UNEP, making the Montreal Protocol one of the most successful global agreements of all time. The UN, however, warns that while the ozone layer is on track to fully recover within four decades, controversial geo-engineering schemes to blunt global warming could reverse that progress.