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 16 September, the International Day for the 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.
The Montreal Protocol was created in 1987 to protect the ozone layer by phasing out the production and consumption of these harmful substances, which is slowly leading to its recovery. Some of the ozone-depleting substances emitted by human activities remain in the stratosphere for decades, meaning that ozone layer recovery is a very slow, long process.
The Montreal Protocol demonstrates the power of international commitment to protecting our environment. Satellite data provide a good means to monitor changes of the ozone layer on global scale. Ozone measurements from the Copernicus Sentinel-5P satellite extend the European time-series that started in 1995 with the Global Ozone Monitoring Experiment (GOME).
