A latest research report from the National Oceanic and Atmospheric Administration (NOAA) in the USA has revealed that the ozone layer is showing signs of recovery. As per NOAA scientists, the concentrations of harmful chemicals that damage the ozone layer has declined by over 50 per cent in the mid-level of the stratosphere compared to that in the 1980s. As reports suggest, the ozone layer may see complete recovery by 2070.This positive milestone in the healing of the ozone layer may be attributed to the Montreal Protocol on Substances that Deplete the Ozone Layer, a pledge signed in 1987 by 46 countries. The treaty went on to be ratified by every country on Earth, which includes as many as 198 United Nations (UN) Member States.The treaty was in response to revelations brought to light by Professors Frank Sherwood Rowland and Mario Molina of the University of California in the 70s. The professors highlighted how the ozone layer in the North and South poles showed a hole 7.7 million square miles in size, predicting that continued damage to the layer would allow excessive UV rays on the earth, affecting the health of humans as well as many other species of flora and fauna on Planet Earth.As the ozone layer acts as a protective shield against harmful UV rays found in sunlight, it was crucial to keep it intact so it could continue to effectively absorb the UV rays. The Montreal Protocol, thus, included a number of steps that went on to be adopted by participating countries, including a ban on Chlorofluorocarbons (CFCs), reduction in the use of Hydrochlorofluorocarbons (HCFCs) and Hydrofluorocarbons (HFCs), all of which were contributing heavily in ozone depletion.Image used for representational purposes only.