News: NASA and US National Oceanic and Atmospheric Administration (NOAA) scientists have reported that the annual ozone hole over the Antarctic has been found to be at its smallest since the 1980s
- Ozone layer, also called ozonosphere is a layer in the stratosphere lying between roughly 15 and 35 km above Earth’s surface, containing relatively high concentrations of ozone molecules (O3).
- By absorbing the harmful ultraviolet radiations from the sun, the ozone molecules protect earth from harmful UV rays which can cause skin cancer and other diseases and deformities, in plants and animals
- It is a region in the stratosphere, directly above Antarctica, where the concentration of ozone has been measured to become extremely low in certain months.
- During experiments in Antarctica in the early 1980s, scientists noticed that during September-November, the concentration of ozone fell considerably lower to what was recorded in the 1950s.
- Studies and satellite measurements confirmed the depletion, and by mid-1980s scientists held a class of industrial chemicals like chloroflurocarbons, or CFCs responsible for depletion of ozone.
- On September 16, 1987, the United Nations and 45 other countries had signed the Montreal Protocol on substances that deplete the Ozone layer.
- The purpose of the Montreal Protocol is to protect the Ozone layer by reducing the production of substances that are supposed to be responsible for Ozone layer depletion.
- The protocol was further strengthened with the ratification of the legally binding Kigali Agreement at the 28th Meeting of the Parties in 2016 in Kigali, Rwanda. It seeks to phase out the production of hydrofluorocarbons (HFCs) that are potent greenhouse gases by the late 2040s.