Ozone hole is now larger than Antarctica: Scientists

The hole in the ozone layer that develops annually over the southern hemisphere is now larger than Antarctica, say scientists from the Copernicus Atmosphere Monitoring Service (CAMS). Earth’s protection shield depletes and forms a hole over the hemisphere every spring due to human made chemicals of chlorine and bromine. However, researchers responsible for monitoring it say that this year’s hole is growing rapidly and is larger than 75% of ozone holes measured since 1979. 

The ozone layer lies about 15-40 kms above the earth’s surface and absorbs harmful rays from the sun, shielding the earth from ultraviolet radiation. Every year, a hole forms during late winter as the sun causes ozone depleting reactions with the human made compounds. While the hole reaches its peak between mid-September to mid-October, the depletion goes back to normal when the temperatures rise up in December that weakens the polar vortex and finally breaks it down.

This year Copernicus said in a statement that the hole “has evolved into a rather larger than usual one”.

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In 1987, the UN had signed a Montreal Protocol on substances that deplete the ozone layer in order to preserve and repair the layer. The agreement banned harmful chlorofluorocarbons and other substances which absorb the UV radiation and this resulted in a gradual healing process of the layer. Scientists predicted that the ozone will heal completely by 2060 when the protocol was signed. 

During recent years with normal weather conditions, the ozone has typically grown to a maximum of 20 million sq km. While the unusually large size doesn’t mean that the overall recovery isn’t going ahead as expected, it still slows down the healing process, says Vincent-Henri Peuch, CAMS Service Director. 

“We cannot really say at this stage how the ozone hole will evolve. However, the hole of this year is remarkably similar to the one of 2020, which was among the deepest and the longest-lasting – it closed around Christmas – in our records since 1979.”

“The 2021 ozone hole is now among the 25% largest in our records since 1979, but the process is still underway. We will keep monitoring its development in the next weeks. A large or small ozone hole in one year does not necessarily mean that the overall recovery process is not going ahead as expected, but it can signal that special attention needs to be paid and research can be directed to study the reasons behind a specific ozone hole event.” he added.

While the harmful chemicals for the depletion like CFCs are banned in 197 countries, other factors like climate change are relatively slowing down the process. However, scientists predict that a full recovery process could be expected at least by 2070.

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