Chlorofluorocarbons are among the various greenhouse gases that are causing the temperature of the Earth to soar. Coincidentally, these are the same gases that were pulled up in the 90s for the role they played in the depletion of the ozone layer. Immediate steps were taken to curb their concentration in the Earth's atmosphere, and they were successful to a significant extent as well. Even though the issue was managed, it did set a new question rolling, is there any relationship between ozone layer depletion and global warming causes?
What is the Ozone Layer?
The atmosphere of the Earth plays a crucial role in making it the only planet with life. Basically, the atmosphere is divided into five layers; stratosphere being one of them. Within the stratosphere, there lies a layer, made of a specialized form of oxygen, known as the ozone layer. The layer is made up of three oxygen atoms, contrary to the usual two oxygen atoms. With no demarcated boundary, the ozone layer is found between 10 to 20 miles above the surface of the Earth. This layer traps the harmful ultraviolet-B (UV-B) radiation emitted by the Sun and hence, plays a crucial role in supporting life on the planet.
What is Ozone Layer Depletion?
The ozone layer is threatened by a range of chemicals which destroy it through a series of chemical reactions. These chemicals, including chlorofluorocarbons, methyl bromide, etc., are released in the atmosphere owing to various anthropogenic causes, including the use of refrigerants (which release CFCs) and insecticides. As these chemicals reach the stratosphere, they destroy the ozone layer. The molecules of these chemicals have the tendency of breaking ozone molecules, thus hampering their ability to trap the ultraviolet-B radiation. The rate at which this layer depletes increases with the decrease in the temperature.
What Does Global Warming Have to Do With Ozone Depletion?
The fact that a fall in temperature increases the rate at which the ozone layer depletes may make a person wonder as to how global 'warming' can cause the ozone layer to deplete, but it does. When we refer to the fact that the global temperatures have soared by 1.8 °C over the last 100 years, we actually refer to the near-surface temperature of the planet. One of the major causes of global warming is the greenhouse effect, wherein a number of greenhouse gases, which are released by natural as well as anthropogenic activities, form a layer in the atmosphere and trap the Sun's radiation, thus making the planet warm.
So the heat that is supposed to be reflected back to the space is trapped within the troposphere. As a result of this, the temperature in the troposphere rises, but the temperature in the stratosphere falls. As the temperature in the stratosphere falls, the ozone molecules in this layer become vulnerable to destruction by the harmful emissions. And therefore, it is said that global warming―though not directly―does play a significant role in the depletion of the ozone layer.
Ozone depletion fueled by falling temperature in the stratosphere is just one of the several hazardous effects of global warming on the Earth. Even though the Montreal Protocol played a significant role in curbing harmful emissions which caused the ozone to deplete, within two decades of signing this protocol we find ourselves on the doorstep of yet another ozone crisis. This time fueled by one of the most hazardous environmental issues threatening the planet, global warming.