A hole in the ozone layer appeared over Antarctica. This layer protects life on the ground from harmful ultraviolet radiation. The hole increased to the beginning of the millennium and caused an increase in the number of skin cancer in the southern hemisphere, especially in Australia and New Zealand.
However, after receiving the Montreal Protocol, the trend reversed, the ozone layer began to renew and the hole healed. Now scientists have announced that around 2035 the hole will be completely healed. While signs of ozone recovery have been observed earlier, the authors of the new study for the first time with high statistical certainty confirm that the main reason is to reduce emissions of substances damaging ozone layer.
“We have long had qualitative evidence that the ozone hole is shrinking. However, this is the first study that precisely quantifies the rate of trust in its renewal. Now with certainty 95 % we can say that the ozone hole is healed,“Explains Dr. Susan Solomon from the Massachusetts Institute of Technology.
The ozone hole was first discovered in 1985. Scientists then found that it opened during Antarctic Spring, between September and December. Soon they also revealed its root cause – chlorofluorocarbon or CFC (CFC), chemicals used in cooling devices, air conditioners, insulating materials and aerosols. The CFC decomposes in the stratosphere and destroys ozone under certain conditions. The discovery led to a rapid reaction – in 1987 the Montreal Protocol was signed, which gradually banned the production and use of these substances.
The first signs of healing the ozone layer appeared in 2016, when the hole began to shrink from year to year. Until now, however, it has not been certain whether it is really worth a CFC restriction or other climate phenomena such as El Niño, La Niña or a polar whirl. “If the trend is maintained and the renewal of ozone will be stronger, we may see around 2035 the year when the ozone hole does not appear at all,“Says Peidong Wang, one of the authors of the study. The study was published in the prestigious magazine Nature.
