Antarctic ozone layer in September with the hole from 1957 to 2001 year (Photo credit: Wikipedia)
Why is the ozone layer so important to us? What is the ozone layer?
The ozone layer is a section within the stratosphere of the atmosphere where the gas o3 is found. The ozone layer is earth’s protective shield which absorbs the harmful UV rays from the sun before they reach us on the surface.
We all know that our mothers told us to wear sun block, or to cover up in the sun and to wear a cap’I do it to my children now. Why? Because the suns rays can cause skin cancer. It would be a whole lot worse if we didn’t have the ozone layer, in fact, without the ozone layer our planet would be reduced to a waste land as temperatures on the surface would not make life sustainable.
Besides for absorbing the UV rays from the sun, the ozone layer also absorbs the infra red rays that the earth reflects back into the atmosphere. This is commonly known as the greenhouse effect
Without this function of the ozone layer, our earth would become too cold to support life.
No wonder environmentalists and greenies worldwide want to protect our atmosphere from ozone layer depletion.
Where is the ozone hole?
(Image courtesy of NASA)
The ozone hole is in the Southern Hemisphere centred over Antarctica. It is not really a gaping hole, but rather an area in the ozone layer that is thinner than the rest of the layer around the globe.
Many people believe that this “hole” is over Australia, but this is incorrect. The size of it does stretch slightly with the seasons but it is generally only over Antarctica.
What caused this ozone layer depletion?
About 20 years ago there was a major outcry against the use of CFC’s or Chlorofluorocarbons. CFC’s were then widely used in products like refrigerators, fire fighting agents, air conditioning and surgical sterilizers. Aerosol cans also made use of CFC’s.
Scientists discovered that these CFC’s , which contain chlorine, can, under certain conditions breakdown ozone into oxygen. And these chlorine atoms were found in the air in the ozone layer above Antarctica.
The banning of CFC’s throughout the world followed, agreed upon by world leaders in 1987 documented in the Montreal Protocol treaty, and subsequently enforced in 1989.
But is this the end of the story?
Now that we are getting rid of CFC’s will the ozone hole repair itself? Well the answer to that is “NO”.
Why not you may ask? Well, what most of the media and the environmentalists do not tell you is about the natural weather phenomenon called the polar vortex
NASA states in their ozone watch website:
“Each year for the past few decades during the Southern Hemisphere spring, chemical reactions involving chlorine and bromine cause ozone in the southern polar region to be destroyed rapidly and severely”. This depleted region is known as the “ozone hole”.
Well, chlorine atoms which are responsible for the depletion of the ozone layer are not seasonal. These atoms are around all the time. When the hole was first discovered by Gordon Dobson in the 1920’s, CFC’s were not that widely used, however the hole was still there, and has worsened in the years since discovery.
Some scientists believe that the ozone layer depletion cannot be traced back to purely CFC usage but is the result of the seasonal winds that blow in the South Pole in August every year. This polar vortex is characterized by a steady rush of wind moving in an upward direction.
Chlorine molecules are much heavier than the surrounding air and as such cannot “float” up into the ozone layer during other times of the year and it is only with this polar vortex that the wind currents are strong enough to actually carry the wrong doers up into the atmosphere over the Antarctic during the Southern Hemisphere spring each year.
It is seen on ozone layer graphs that the hole deepens for only a few months of the year and then by November the ozone levels return to their first recorded levels.
The way forward?
Hopefully this article will give you a more balanced less hysterical look at ozone layer depletion. Does this mean we can sit back on our laurels and use products that are harmful to our atmosphere. Most definitely not, but again I encourage visitors to this site to not always believe everything you see in the media but to carefully research both sides of each green concern and act accordingly.
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