In the 1970s scientists noted significant stratospheric ozone loss above Antarctica, but dismissed the concern with the conclusion that it was just an uncertainty.
It was only in the mid-1980s that scientists took the ever-growing ozone hole as a serious problem for climate change.
The ozone layer is extremely important for the Earthís climate processes as it not only keeps the Earth’s surface warm and habitable, but also protects humans from direct contact with the Sun’s ultraviolet radiation. This prevents humans from growing skin cancer, cataracts and suppressing immune systems.
Despite the need of sunlight for photosynthesis, plant life is also damaged by intense ultraviolet radiation.
Thus, the ozone layer plays a major role in absorbing ultraviolet radiation to decrease the amount of ultraviolet radiation reaching the Earth’s surface. Man-made chlorofluorocarbons (CFCs) used in refrigerators, aerosols, air-conditioning and packing materials are the root cause behind ozone destruction.
The CFCs rise into the stratosphere where the Sunís ultraviolet radiation photolyses the CFCs, releasing chlorine atoms that react with the ozone molecules and destroy them.
NASA scientist, Anne Douglass said, “CFCs have lifetimes from 50 to 100 years, and so they linger in the atmosphere for a very long time.” Without a doubt, the accumulation of CFCs creates a large reservoir of chlorine in the atmosphere, which increases the growth of the ozone hole.
Just recently, NASA has confirmed that the ozone hole is healing and in fact shrinking.
Susan Strahan, scientist from NASA’s Goddard Space Flight Centre in Greenbelt, Maryland said: “We see very clearly that chlorine from CFCs is going down in the ozone hole, and that less ozone depletion is occurring because of it.”
This may possibly be the long-awaited outcome of the Montreal Protocol in 1987 where all participating countries agreed to phase out CFCs in their respective countries.
The ozone hole is expected to gradually decrease over the next few decades, giving humanity hope in saving our planet. Anne Douglass said: “As far as the ozone hole being gone, weíre looking at 2060 or 2080. And even then there might still be a small hole.”