Recent claims that the hole in the ozone layer is recovering have received worldwide media attention. But the continuing decline of ozone concentrations in the stratosphere and the return of a huge ozone hole over Antarctica raises doubt about claims that it is ‘healing.’
In 1989, the so-called Montreal Protocol introduced a ban on ozone-depleting chlorinated and brominated hydrocarbons such as CFCs. These substances have been blamed for the ozone hole which scientists discovered in the second part of the 20th century.
In the years following the ban the loss of stratospheric ozone seemed to have stopped and in recent years the ozone hole was declared to be shrinking and ‘healing.’
In fact, scientists have been expecting that the global ozone layer would completely recover within decades.
However, researchers recently discovered that despite the ban on CFCs, the concentration of ozone in the lower part of the stratosphere has continued to decline at latitudes between 60 degree South and 60 degree North.
The return of a huge ozone hole over Antarctica is one of the largest and deepest this century.
The ozone layer is a part of the Earth’s atmosphere and acts as a shield, absorbing harmful ultraviolet radiation from the sun.
However, chemicals and substances created by humans have led to thinning in the layer, known as ozone holes.
Scientists from the European Union’s Copernicus Atmosphere Monitoring Service (CAMS) have said the return of a large hole, following an “unusually small and short-lived” one in 2019, shows the need to enforce the global Montreal Protocol.