Ozone layer is healing
#GS-03 Environment Conservation
- Ozone (O3) is a highly reactive gas composed of three oxygen atoms and is much less stable than its diatomic allotrope O2.
- Ozone can be found as both naturally occurring and as a man-made
- Natural ozone is generally found in the Earth’s upper atmosphere (the stratosphere) while the man-made ozone is in lower atmosphere (the troposphere).
- Stratospheric ozone is formed when the solar ultraviolet (UV) radiation falls on the molecular oxygen (O2) in the upper atmosphere.
- Tropospheric or ground-level ozone is created primarily from photochemical reactions between two major classes of air pollutants i.e., volatile organic compounds (VOC) and nitrogen oxides (NOx).
- Stratospheric ozone layer spans approximately 6 through 30 miles (15-35 km) above the Earth’s
- The stratospheric ozone is known as Good Ozone as they help in protecting mankind from the harmful UV radiation from the Sun.
- The tropospheric ozone is called Bad Ozone since it is an air pollutant and is harmful to lungs and it damages crops, trees and other vegetation.
- Ozone is a trace gas in the atmosphere having only about 3 molecules for every 10 million molecules of air.
Ozone-Depleting Substances (ODS)
- Ozone-Depleting Substances (ODS) are chemicals that have the capacity to cause gradual thinning of the earth’s ozone layer present in the stratosphere.
- The commons ODS are chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, and methyl chloroform.
- Montreal Protocol on Substances that deplete the Ozone Layer 1987 and its succeeding amendments were negotiated in order to reduce the consumption and production of Ozone-Depleting Substances (ODS).
- India became a signatory to the Protocol in 1992.
- 2016 Kigali Amendment to the Montreal Protocol aims to phase down the production and consumption of some HFCs in order to reduce the projected global warming increase and associated climate change.