The ozone depletion refers to the thinning of the ozone layer in the stratosphere, which protects the Earth from harmful ultraviolet (UV) radiation from the sun.
The main cause of ozone depletion is the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS) into the atmosphere. CFCs are chemicals that were widely used in refrigeration, air conditioning, and as solvents. When these chemicals reach the stratosphere, they are broken down by UV radiation and release chlorine atoms, which then react with and destroy ozone molecules.
In addition to CFCs, other ozone-depleting substances include halons (used in fire extinguishers), carbon tetrachloride (used as a solvent and cleaning agent), and methyl chloroform (used as a solvent).
The ozone hole over the Antarctic is a well-known example of ozone depletion. This hole forms each spring as a result of the combination of very low temperatures in the stratosphere and the presence of ozone-depleting substances. The hole has grown larger over the years and has now expanded to cover an area that is roughly equivalent to the size of North America.
The effects of ozone depletion can be serious and include increased rates of skin cancer, cataracts, and other health problems, as well as damage to crops and other living things. In response to the growing threat of ozone depletion, the international community took action by signing the Montreal Protocol in 1987, which led to the phasing out of the production and consumption of ozone-depleting substances. As a result of this action, the ozone layer is expected to recover over the next several decades.