According to Europe’s MetOp weather satellite, which is monitoring the atmospheric ozone, the hole over the South Pole in 2012 was the smallest in the last 10 years. The hole has been developing since the 1980s and the concentration of the layer has reduced by as much as 70 per cent.

The depletion in the Ozone layer is more prominent in the South Pole as compared to the Arctic Circle because of high wind speeds that results into a fast-rotating vortex of cold air which leads to lower temperatures. The chlorofluorocarbons (CFCs) affect the Ozone more strongly in lower temperatures thereby creating holes like the one present over the Antarctica today notes the European Space Agency.

In the North Pole, the effect of CFCs is comparatively less because of irregularities in the landmasses of the northern hemisphere. The presence of mountains prevents build-up of strong winds unlike the South Pole and hence the Ozone depletion is not that prevalent here.

The decrease in size of the hole is probably the direct result of reduction in the concentration of CFCs, especially since the mid-1990s, because of international agreements like the Montreal Protocol.