According to observations by NASA scientists, the ‘hole’ in the ozone layer of our atmosphere has finally started closing up. At present, the hole is 12 million miles wide, but within three decades the hole will be left eight million miles wide. If the environmental conditions remain good, it could disappear by the end of the century.

NASA's Aura satellite and Suomi NPP partnership satellite have measured the ozone in the southern hemisphere for each year from 1979-2013, except 1995.

A report published in the journal Geophysical Research has come as a proof of the effectiveness of the Montreal Protocol that was started in 1987 to limit the use of gas propellants like chlorofluorocarbons (CFCs) worldwide and protect the ozone layer.

Susan Strahan, a senior research scientist at the NASA Goddard Space Flight Center, said, “With this new information, we can look into the future and say with confidence that ozone hole will be consistently smaller than eight million square miles by 2040”.

According to the US Environmental Protection Agency, the CFCs released by the products were found to interact with UV radiation to release chlorine, which in turn led to the destruction of the ozone layer. One atom of chlorine can destroy over 100,000 ozone molecules.

It was in 1985 when the scientists from the British Antarctic Survey first reported observations of large losses of ozone over Antarctica.

As the wind currents were sweeping the CFCs toward the poles, the effect was pronounced there as the polar vortex, trapping the chemicals which accumulated over time to high concentrations.

NatGeo said that when the sun shines for long periods of the day, chlorine reacts with ultraviolet rays and destroys ozone on a massive scale of up to 65%, creating the hole seen by the BAS team.