On February 8th 2013, scientists from European Space Agency (ESA) announced that their weather satellite that is equipped with an instrument specifically designed to sense ozone concentrations revealed that the seasonal ozone 'hole' above the Antarctica had shrunk to record levels!
This revelation is being met with much enthusiasm because ozone, a molecule made of up three oxygen atoms that forms a protective layer about 12-19 miles up in the stratosphere, is a natural sunscreen which prevents the sun's harmful ultraviolet rays from reaching the Earth's surface. Without it, humans would be even more susceptible to sunburn and skin cancer.
The best part is that the reversal can be directly attributed to the timely action taken by government officials all over the world, to phase out human-produced chlorofluorocarbons, an organic compound that was used in aerosols and refrigeration.
The ban was imposed in the 1980's, when scientists monitoring the ozone that the protective layer was depleting around the globe. What was even more concerning is that from September to November, it got to such low levels above the South Pole, that they began to call that area the ozone hole.
The reason for this seasonal phenomenon is attributed to the cold air over the Antarctica in winter that creates a huge 'whirlpool' or rapid-moving air called the 'Antarctic vortex'. This locks in that body of air, preventing the outside ozone-rich air from coming in. Not only that, the offensive CFC's that are locked inside the vortex are extra efficient at destroying the ozone in frigid temperatures.
While a similar vortex forms over the Arctic, high altitude winds from the mountain ranges in the Northern Hemisphere, end up pushing the vortex off the pole and letting the warmer air seep in. Therefore, the North Pole does not suffer the same seasonal phenomenon.
Though it will take years for the effects of old CFC's to wear off and restore the world's ozone concentration to the level it was in the 1960's, scientists believe that the hole over the Antarctica will be completely repaired, within the next few decades.
The fact that we could turn around what could have become a major catastrophe, by simply changing our destructive habits, gives us hope that if prompt action is taken to reverse global warming, the same can be achieved there too!
resources: livescience.com, earthobservatory.nasa.gov