: There are two main causes of ozone depletion. Namely- a) Natural causes b) Man-made causes. These are discussed below - (a) Natural causes: The natural causes responsible for the depletion of the ozone layer are - 1. Lightning 2. Agnudgam 3. Photochemical reaction 4. Effects of ultraviolet rays etc. All of these factors lead to the destruction of the ozone layer by breaking down ozone gas molecules through the following processes. However, it is important to keep in mind that just as the ozone layer is depleted by natural causes , it is also formed by natural causes. So the natural causes behind the depletion of the ozone layer do not have such a serious effect. (B) Man-made factors: Man-made factors are largely responsible for the depletion of the ozone layer. These are as follows - a) Chlorofluorocarbon ( CFC): Chlorofluorocarbon ( CFC) or freon is a special compound that is particularly responsible for the depletion of the ozone layer. It is again of three kinds ; Namely - CFC-11 (CFCl3), CFC-12 (CF2Cl2), CFC-113 (CF2Cl.CF2Cl); Since 1995, experts have blamed chlorine emissions for the depletion of the ozone layer. A chlorine atom remains unchanged after breaking down about one million ozone molecules. O3 + Cl> O2 + O + Cl Source: CFCs are emitted from the fields of refrigerators , air conditioners , foam industry , paint industry , plastics industry , perfume industry , circuit cleaning of computers and other devices . Also toxic black smoke from factories and vehicles , tannery waste which later plays a role in producing chlorine gas in the atmosphere through various chemical reactions. b) Nitrous oxide ( N2O): Nitrous oxide is another important gas which plays a role in ozone depletion. Source: Use of chemical fertilizers in agriculture , vehicles , nylon industry etc. c) Nitrogen oxide ( NO): Nitrogen oxide is another important element responsible for depletion of ozone layer . Source: jet plane d) Bromine atom: Bromine atom is formed when the halon compound breaks down under the effect of ultraviolet rays. These bromine atoms act as ozone destroyers. Source: Fire Extinguisher e) Sulfur Particles: Sulfur particles are one of the factors responsible for ozone depletion. Sources: Factories , vehicle exhaust fumes etc. In addition to the factors mentioned above, f) methane , g) methyl bromide , h) methyl chloride etc. are other man-made causes of ozone depletion. At last we have come to realize that man-made causes are the cause of the depletion of the ozone layer in the atmosphere.