Today you can’t pick up a newspaper or watch a nature programme without hearing about global warming and the damage we are doing to our planet.
However this isn’t the first natural calamity, caused by man in the modern era – until a decade ago it was all about “the Ozone Layer”.
What is Ozone ?
Ozone (O3) is a highly reactive gas composed of three oxygen atoms. It is both a natural and a man-made product that occurs in the Earth’s upper atmosphere (the stratosphere) and lower atmosphere (the troposphere)
Why Do We Need the Ozone Layer?
It acts as a very thin shield high in the sky that protects us from the Sun’s harmful ultraviolet (UV) rays. Too much UV light reaching the Earth’s surface can cause: skin cancer and possibly eye damage (especially cataracts) and weakening of the immune system, to name a few. Harm to the Immune system means a harder time fighting off diseases.
Most of the ozone is in a layer that starts 6 miles above the surface of the Earth and goes up to about 30 miles. The ozone layer is also very good at blocking UV-B rays, which are the rays that cause sunburn and most skin cancers.
In was in the 1970s, that scientists noticed that some of the ozone was being depleted. However by this time the damage had already been done and a hole in the ozone layer over the Antarctic was discovered in 1985.
The main culprit was chlorofluorocarbons, or CFCs, which are used to keep things cold and to make foam and soaps. Many of these “bad guys” were released in the air, mainly from fire extinguishers, aerosol spray cans, manufacturing facilities, refrigerators, air-conditioning units, and dry-cleaning establishments.
CFCs are very stable at low altitudes, so they stay in the atmosphere long enough to diffuse into the stratosphere. Up there, UV rays are strong enough to break them down and release chlorine. Each chlorine atom can attack and break apart thousands and thousands of ozone molecules. So just a small amount can do major damage.
Despite the fact that countries around the world knew the damage that that CFCs were doing to the environment little worldwide action was taken until 1987, when an international treaty, called the Montreal Protocol, sharply limited the production of CFCs.
They were completely phased out in the developed world by 1996.
And Now … the Good News
Humans have the capability to do damage to our planet Earth, but we also have the knowledge to protect our home, if we’ll use it
Three satellites and three ground stations have shown that the depletion of the ozone layer is actually decreasing. Nature is repairing the damage, and ozone levels started to rise ever so slightly in late 2009 in most parts of the world. It will be 50 years before all the damage is repaired.
Humans have the capability to do damage to our planet Earth, but we also have the knowledge to protect our home, if we’ll use it.
So take heart, maybe we can do something about our new nemesis – global warming as well.