The 2021 ozone hole evolution appears to be similar to last year’s size, currently around 23 million sq km – reaching an extent larger than Antarctica. According to CAMS, the 2021 ozone hole has considerably grown in the last two weeks and is now larger than 75% of ozone holes at that stage in the season since 1979. This map is centered on the Antarctic region. Areas colored yellow, orange, and red depict high ozone values, whereas green and blue areas show low values. Credit: Copernicus Atmosphere Monitoring Service/ECMWF
World governments agreed in the late 1980s to protect Earth’s ozone layer by phasing out ozone-depleting substances emitted by human activities, under the Montreal Protocol. The phase-out of these substances has not only helped protect the ozone layer for future generations but has also protected human health and ecosystems by limiting the harmful ultraviolet radiation from reaching Earth. On September 16, the International Day for Preservation of the Ozone Layer, we take a closer look at this year’s ozone hole.
The ozone layer in the atmosphere protects Earth from potentially harmful ultraviolet radiation. In the 1970s, scientists discovered that the ozone layer was being depleted.
Atmospheric conditions of ozone vary naturally depending on temperature, weather, latitude, and altitude, while substances ejected by natural events such as volcanic eruptions can also affect ozone levels. However, these natural phenomena couldn’t explain the levels of depletion observed and it was discovered that certain human-made chemicals were the cause.
Ozone depletion is greatest at the South Pole. This depletion creates what is known as the ‘ozone hole.’ From August to October, the ozone hole increases in size – reaching a maximum between mid-September and mid-October.
