The main reason for the destruction of the ozone layer is the atmospheric pollution caused by man-made chemical products, such as Freon. Freon gas is lighter than air. Once released, it will slowly rise to the top of the ozone layer in the earth's atmosphere.
At the top of the ozone layer, the ultraviolet ray will decompose the chlorine atom in the freon gas, and the chlorine atom will take away an oxygen molecule in the ozone and turn the ozone into oxygen. The ozone is destroyed and loses the ability to absorb ultraviolet rays. The uncontrolled use of chemical fertilizer in agriculture will produce a large amount of nitrogen oxide, and the combustion of various fuels will also produce a large amount of nitrogen oxide. These substances will destroy the ozone layer, pose a potential threat to the survival of organisms on the earth, and endanger the ecological environment and human survival.