The ozone layer is healing — but it could take another 50 years to completely recover

• According to a 2018 study, portions of the ozone layer have recovered at a rate of 1% to 3% per decade since 2000.
• At this rate, Northern Hemisphere and mid-latitude ozone are likely to recover completely in the next 10 years.
• When the fragile Ozone layer depletes, the sun’s ultraviolet rays can reach Earth — making humans more susceptible to skin cancer, cataracts, and other diseases.
  

The ozone layer is slowly healing. In 1987, all the countries in the world promised to save the ozone layer together. And, it has worked, in parts.

According to the latest Scientific Assessment of Ozone Depletion, completed in 2018, portions of the ozone layer have recovered at a rate of 1% to 3% per decade since 2000.

At this rate, Northern Hemisphere and mid-latitude ozone are likely to recover completely in the next ten years. Whereas, the Southern Hemisphere will recover by 2050s and the polar regions by 2060s.

Experts estimate that 2 million cases of skin cancer cases globally are likely to be prevented each year by 2030.

“On this World Ozone Day, we can celebrate our success. But we must all push to keep hold of these gains, in particular by remaining vigilant and tackling any illegal sources of ozone-depleting substances as they arise,” United Nations wrote.

The United Nations (UN) is celebrating this year’s World Ozone Day, commemorating the three decades of international cooperation to protect the ozone layer and the climate under the Montreal Protocol.

The connection between CFCs and the ozone layer
Almost five decades ago, three chemists — Mario Molino, Sherwood Rowland, and Paul Crutzen — warned that chlorofluorocarbons (CFCs) pose a threat to the ozone layer that protects humans, animals and plants from harmful sun radiation.

When the fragile Ozone layer depletes, the sun’s ultraviolet rays can reach Earth — making humans more susceptible to skin cancer, cataracts, and other diseases.

The discovery shook the world, making the headline worldwide. Although there was widespread denial by CFC manufacturers, aerosol sales dropped significantly.

Fifteen years later, a British team discovered a giant hole in the ozone layer above Antarctica. At the same time, the National Aeronautics and Space Administration (NASA) found a connection between the ozone layer hold and CFCs.

These discoveries led to the 1987 Montreal Protocol — an agreement that bans chlorofluorocarbons and another ozone-depleting chemical. Later in 2016, hydrofluorocarbons were also added to the list of banned substances.

A long road to recovery
While the results are positive, it will still take another 50 years for the ozone layer to completely heal. This is because CFCs and other manufactured chemicals can remain present in the atmosphere for about 50 to 100 years. Had the measures not been implemented, two-thirds of the ozone would have been destroyed by 2065, according to Paul Newman, NASA.

But we should not be celebrating — at least for now. Recently, scientists discovered the biggest hole ever incurred in the ozone layer above the Arctic.

According to media reports, the ozone layer is relatively smaller than the one on Antarctica. Antarctica’s ozone hole can grow up 25 million square kilometres, but this one is spread in less than a million square kilometres. And this was caused by extreme weather events.

Researchers are now looking at whether climate change can deplete the ozone layer further.

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