What happens if the ozone layer disappears?


We received the following question from one of our subscribers:

The question is quite interesting, so in this article we will give a detailed answer to it, and also find out what will happen to the Earth if the ozone layer nevertheless disappears completely.

The ozone layer surrounds the Earth and is 15 to 30 kilometers above its surface. At different latitudes of the Earth, the ozone layer is located at different levels. For example, in the tropics — at an altitude of 25-30 kilometers, and in the Arctic circle — from 15 kilometers.

The ozone layer is, as you might have guessed, filled with the gas ozone, also known as trioxygen. It is formed when molecules of ordinary oxygen O2 are split under the action of solar radiation into two free atoms, which bind with other oxygen molecules, forming molecules of ozone O3.

Ozone together with oxygen molecules absorb up to 99% of ultraviolet radiation that is harmful to us and all living organisms from the sun, converting it into heat (The danger of exposure to ultraviolet radiation on the cell is that it damages DNA molecules, which absorbs ultraviolet light more strongly protein molecules).

Scientists believe that this shield was formed about 850-1850 million years ago. In their opinion, it was the process of the formation of the ozone layer that allowed microorganisms to rise from the ocean floor and come to land.

The ozone hole is not a “hole” in the literal sense, that is, it does not have a clear outline. This is a general abstract expression, which implies a decrease in the concentration of ozone in the ozone layer. Most often, such a hole is noticed in Antarctica, but why?

The formation of an ozone hole over Antarctica is caused by very low temperatures, minimal sunlight, harmful chemicals that destroy the ozone layer, and polar vortices.

Stratospheric polar vortices over the South Pole, together with low temperatures for a long period of time, contribute to the formation of a large area of polar stratospheric clouds and the occurrence of chemical processes that also destroy the ozone layer.

Human activities lead to a large amount of emissions of halogen gases containing chlorine and bromine atoms. These emissions, when interacting with ozone, lead to its destruction. At the same time, there is an opinion that the sources of halogens, which reduce the concentration of ozone in the ozone layer, are more natural than anthropogenic. Also, after the signing of the Montreal Protocol, human emissions of halogens are gradually decreasing.

In addition, freons used as a refrigerant also reach the stratosphere and destroy ozone molecules, however, their contribution is not so significant, and due to the action of the same Montreal Protocol, freon emissions are now minimized.

Since the ozone layer protects living organisms from excessive UV radiation, the disappearance of the ozone layer will lead to the destruction of DNA molecules, which will lead to disruption of cell division in animals and humans, mutations, skin cancer, cataracts, weakening of the immune system and other diseases. In addition, living organisms will receive severe sunburn in a matter of seconds in direct sunlight.

Because of this, in a few days after the disappearance of the ozone layer, many plants will die. Without plants, all food webs will collapse. Herbivores will starve, and with their death, omnivores and carnivores will also lose their food source, which will lead to the widespread extinction of all species. Life will become possible only in the depths of the ocean or underground.

Author: Alexey Nimchuk. Edited by Fedor Karasenko.

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