Antarctic ozone hole

The Antarctic ozone hole refers to a significant thinning of the ozone layer over Antarctica, primarily observed since the late 1970s. The ozone layer, located in the stratosphere about 15 to 35 km above Earth, is crucial for blocking harmful ultraviolet (UV) radiation from the sun.12

The depletion is caused by ozone-destroying chemicals (ODCs), particularly chlorofluorocarbons (CFCs). In the stratosphere, UV radiation breaks down CFCs, releasing chlorine atoms that then destroy ozone molecules. This process is exacerbated by the extreme cold within the Antarctic polar vortex, which facilitates the formation of polar stratospheric clouds that convert less reactive chlorine compounds into more reactive forms.134

In response, the Montreal Protocol was established in 1987, leading to a global phase-out of CFCs and other ODCs. Scientists have observed the first signs of recovery, with the ozone layer projected to return to pre-1980 levels by 2066 over Antarctica.15