Ozone depletion is the reduction of ozone in the stratosphere caused by chlorofluorocarbon (CFC) molecules emitted by refrigerators, air conditioners, sprays, etc. that contain chlorine, fluorine, and carbon atoms. These molecules rise to the high altitude of the ozone layer where they react with highly energetic photons, resulting in the depletion of the layer over the Antarctic beginning at the start of Southern Hemisphere spring (August–October) and creating the so-called ozone hole. The ozone layer is extremely important for life on earth because it protects it from deadly solar radiation and has thus allowed organisms to move out of the oceans and onto land.
Fortunately, many governments recognized the danger posed by CFCs to the ozone layer, and international agreements were made and acted upon in the 1980s to reduce their production. These chemicals were replaced by hydrofluorocarbons (HFCs). Although the ozone layer is beginning to recover, it is likely to take until the 2060s for the ozone-depleting chemicals to completely disappear from the atmosphere.