NASA’s Aura satellite results indicate that the infamous ozone hole is reducing in size, a good sign for the earth.
- NASA’s Aura satellite shows that the ozone hole over Antarctica is gradually reducing in size.
- There was 20 percent less ozone depletion in 2016 compared to the depletion levels 9 years before.
- The achievement is a result of the ban on chlorofluorocarbons which was adopted by several nations according to the Montreal Protocol.
Chlorofluorocarbons and the Ozone Hole
Chlorofluorocarbons or CFCs were one of the common compounds back in the 1980s to be used in aerosol sprays, refrigerants, solvents, and other products. In the upper layer of the atmosphere chlorine containing CFCs break down to produce inorganic chlorine which further breaks down the protective ozone layer that protects the earth from the sun’s harmful radiations. One CFC molecule can destroy 100,000 ozone molecules and their long life span means that they could persist in the atmosphere for decades.Recovery of the Ozone Hole
NASA’s satellite data suggests that the ozone hole over Antarctica is slowly reducing in size. According to the Montreal protocol, ozone recovery requires two things to happen:- Chlorine levels in Antarctica need to decline
- There needs to be a reduction in ozone depletion as a result of chlorine decline
"We may have turned the corner on O3 depletion," says Dr. Susan Strahan, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the lead author of the study. “But it's important that all the nations of the world continue to abide by the Montreal Protocol (and its amendments) that ban CFC production."
The recovery is slow due to the long life of CFCs, which can remain in the atmosphere for decades, but the team believes that they expect the ozone hole to be gone between 2060 and 2080.
The benefits
Any rise in atmospheric ozone levels is expected to bring major benefits to life on earth.- Blocks ultraviolet radiation responsible for problems from cataracts to skin cancers.
- Blocks the adverse effects of UV radiation on crop yields.
- Strengthens the belief that sends across a reminder that international collaborations can solve even the greatest environmental and public health problems.
References:
- The good news about the ozone hole is even better than you think - (http://www.euronews.com/2018/01/09/good-news-about-ozone-hole-even-better-you-think-ncna835971)
- Strahan, S. E., & Douglass, A. R. (2017). Decline in Antarctic ozone depletion and lower stratospheric chlorine determined from Aura Microwave Limb Sounder observations. Geophysical Research Letters, 44. https://doi.org/10.1002/2017GL074830