When it comes to
bad news about climate change, there is never a shortage. From air pollution to
rising global temperatures, there has never been positive news and the
solutions have always seemed farfetched. But
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.
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:
O, Aura Microwave Limb Sounder demonstrated that inorganic
chlorine from 2013 to 2016 was 223 ± 93 parts per trillion lower
in the Antarctic atmosphere than during the years 2004 to 2007. This brings the
9 year annual rate of inorganic chlorine decline to 25 ± 10 ppt/yr (~0.8%/yr).
The study also observed a reduction in ozone depletion in response to chlorine
decline.
‘The decline in depletion of the ozone layer insists on the fact that science when combined with right policy making can solve even the greatest environmental and public health challenges.’
Experts believe that this major
achievement is the result of the series of international regulations and
collaborations of several nations to ban the use of CFCs.
"We may have turned the
corner on O
3 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.
Strahan concludes saying,
"Science and policy CAN work together to solve global problems. I think
people need to know this so they won't be discouraged about solving climate
change."
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
Source: Medindia
