"Without the earth's Ozone Layer, We will cease to exist"
The earth is blessed with clean air, water, as well as food. It is also provided with an excellent resource of atmosphere - to block harmful Ulta-Violet (UV) radiation, moderates climate; keeping the earth's surface warm by delaying outgoing infrared radiation and redistributes water to the hydrologic cycle. All of these permitted the existence of life on earth.
The atmosphere is a sea of gas that plays a role in maintaining the balance of life on earth. This gaseous covering has promoted growth and participated in the proliferation of organisms in unique ways.
Part of the protective layer of the atmosphere is the Ozone layer. Ozone makes it difficult for the incoming harmful UV rays from the sun to penetrate into the earth's surface. Naturally, the ozone is constantly being created and destroyed through photochemical degradation at a certain period of time. But due to anthropogenic activities, the depletion of the ozone layer is accelerated, allowing the harmful rays to potentially damage life on earth.
What is responsible for the catalytic depletion of Ozone layer in the Stratosphere?
In the early 1930's, Chlorofluorocarbon (CFCs) molecules and Halons containing Bromine atoms was first introduced and used for many applications such as, refrigerants, aerosols, and manufacture of materials, like fire-extinguisher equipment and styrofoam. They were thought to be safe and environmentally neutral since they are chemically inert, nonreactive, and will not undergo chemical reaction under a set of given conditions. Later, it was found out that these chemicals destroy the ozone upon reaching the stratosphere.
When CFCs reach the stratosphere, the very high energy of UV (ultra-violet) radiation causes the degradation of CFC, leaving a free chlorine atom. The chlorine atom then breaks up ozone molecules by combining with oxygen atom resulting to a catalytic chemical reaction. The chlorine atoms are recreated in subsequent reactions. One chlorine atom can destroy 100,000 ozone molecules. Degradation of halons leaves a free bromine atom that destroys ozone in the same way as chlorine. Depleting the Ozone layer.
The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules.
If anthropogenic activities that put CFCs and other ozone-destroying chemicals into the stratosphere are stopped completely, the ozone layer may eventually repair itself.
What will happen if the Stratospheric Ozone reaches its minimum level of concentration, or worse, if its totally exhausted?
Most scientists concurred that without the earth’s ozone layer, we would all cease to exist. "Life, as we know it, would be destroyed." Without the protection of the Ozone layer from harmful UV rays, we would be susceptible to diseases and cell damage.
Anne Rammelsberg, a chemistry professor at Millikin University, said:
"Ultraviolet (UV) light kills cells by damaging their DNA. If the damage is not too extensive, cancerous or precancerous cells are created from healthy cells. If it is widespread, the cell will die."
Land and Water life would suffer. Animal, plant and even marine life would not be safe since UV rays can penetrate clear water to a certain depth before being absorbed.
Skin cancer and Other health risks. The main factor that causes skin cells to become cancer cells is through exposure to UV radiation.
Skin cancer develops in the cells in the epidermis – the top or outer layer of the skin. UV radiation is made up of UVA and UVB rays which are able to penetrate the skin and cause permanent damage to the cells.
UVA penetrates deeply into the skin (the dermis) causing genetic damage to cells, photo-ageing (wrinkling, blotchiness, etc.) and immune-suppression.
UVB penetrates into the epidermis (top layer of the skin) causing damage to the cells. UVB is responsible for sunburn – a significant risk factor for skin cancer, especially melanoma.
Disruption of Food Chain. High levels of exposure to UV-B can stunt the growth and photosynthesis of a variety of crops such as maize, rye and plants like, sunflowers. It can also affect the reproductive capacity of land and aquatic life. Leading to the disruption of our food chain.
However, thanks to the initiatives such as, Montreal Protocol, research carried out for the United Nations Environmental Programme showed that ozone levels had not fallen further between 2002 and 2005.
Hello Steemians! Thank you for reading, I hope you learned something. I'm sorry I wasn't able to post recently, I was busy at school doing projects, assignments and exams. I hope you keep updated. Stay hydrated everyone and put some sunscreen on! :)
References:
http://www.tutorvista.com/content/biology/biology-iv/natural-resources/atmospheric-resources.php
https://www.cancercouncil.com.au/63295/cancer-prevention/sun-protection/sun-protection-sport-and-recreation/sun-protection-information-for-sporting-groups/how-ultraviolet-uv-radiation-causes-skin-cancer/
https://www.uow.edu.au/~sharonb/HoleStory/intro/intro3.html
http://www.ozonedepletion.co.uk/what-will-happen-life-earth-if-ozone-depletion-continues.html
https://www.scientificamerican.com/article/how-does-ultraviolet-ligh/