The ozone layer is a thin part of the Earth that protects the earth from the sun’s harmful ultraviolet rays.
The ozone layer acts like a sponge as it absorbs a type of the sun’s radiation called ultraviolet radiation (also called UV light) which can have harmful effects on people, plants, and animals on earth.
However, global warming has caused, what’s called ozone holes in many places. These holes allow the UV rays to enter the earth’s atmosphere which are harmful to people.
Don’t we need some of the sun’s radiation?
We do. But not as much as the sun emits. We need some of it, but too much can be damaging.
Is this the first hole discovered?
No. Earlier, scientists had discovered a large hole over Antarctica, but recently a hole that is some seven-times bigger has been discovered in the lower stratosphere over the tropics.
What is the ozone hole?
First, we need to know that what we call an ozone hole is not a real hole, but a part or portion in the layer where ozone is thinner in comparison to others.
This depletion (thinning) of the ozone is usually in the poles.
What causes an ozone hole?
A chemical called Chlorofluorocarbon (CFC) is the main reason for ozone holes or ozone layer depletion. In the Earth’s atmosphere, approximately 80% of CFCs are emitted by man-made substances.
What are CFCs?
Chlorofluorocarbons (CFCs) contain carbon, chlorine, and fluorine.
They are found everywhere. One example is cooling machines like air conditioners, coolers, refrigerators, chillers, etc. These emit CFCs in the air and this gas stays in the lower atmosphere for a long time. And once this gas reaches the stratosphere, it causes ozone layer depletion.
(the stratosphere is the second layer of the atmosphere as you go upward from the earth)
How do they affect the ozone layer?
This is how it happens..
The ozone molecules are made of three joined oxygen atoms. These are continuously being destroyed and reformed naturally.
However, when the CFCs reach the ozone layer, their molecules don’t let the ozone molecules reform after being broken apart. And that causes the thinning or the “holes”
Is the ozone hole harmful?
Yes – ozone holes can cause catastrophic effects on the earth.
The UV light that hits the earth can cause the DNAs of human beings, plants, as well as other microorganisms to get altered.
There can be severe effects on the skin leading to skin cancers or even cataracts because of ultraviolet radiation. The immunity level of all living beings can also go down. Also, agricultural products can be impacted. Further aquatic life living nearer to the surface like algae, crabs, shrimps, etc would also face various problems.
A new hole discovered
A scientist from the University of Waterloo, Qing-Bin Lu, recently discovered a massive hole over the tropics, which, it seems, has been there for 30 years and is only just discovered! Lu also reported that this hole is seven times larger than the Arctic Ozone hole.
Present since the 1980s, this hole reached its maximum size in the 2000s, with an almost 80% loss of ozone in the center of the hole.
Healing of the ozone layer
In 1987, an agreement called the Montreal Protocol was signed by many countries. Its main aim was to save the ozone layer.
In the protocol, substances like CFCs, halons, carbon tetrachloride, and methyl chloroform were targeted as the main causes of ozone layer depletion. Thus, this meet was focused on reducing the use of these elements. It has somewhat achieved its goal as the hole above Antarctica is healing.
However, that is not near enough and a lot remains to be done to stop the emissions of harmful gases into the atmosphere.