Thread by @weatherindia

#WorldOzoneDay | Remember Geography classes?

Tell us your one memory of #ozonelayer from those classes in the comments section below.

Not necessarily nerdy, they can be fun too.

#WorldOzoneDay: 35 Years On, Story of Ozone Hole and Recovery Sparks Inspiration for Effective #ClimateAction - by @deekshith_np

weather.com/en-IN/india/en…

(📸: NASA's Goddard Space Flight Center)

What is the ozone hole, how did we discover it, and how did we address it? The story is truly inspiring!

#WorldOzoneDay #OzoneDay #OzoneLayer

The ‘hole’ story

The story goes back to 1776 when a French chemist named Antoine Lavoisier first proved that oxygen is indeed a chemical element.

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Following this discovery, several experiments were conducted with oxygen, and one particular experiment of passing electricity through oxygen gave up some intriguing results.

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The experiment produced a strange slightly pungent-smelling chemical that, in the 1830s, a German-Swiss chemist Friedrich Schönbein named as ‘ozone’, meaning ‘to smell’ in Greek.

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In 1913, French scientists Charles Fabry and Henri Buisson discovered that the ozone collects in a layer in the stratosphere, roughly 18 km above Earth’s surface.

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While the science behind the ozone layer is a century old, it was only by the 1970s that scientists started to notice the impact of CFCs on this roof of life.

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Shockingly, in 1985, Joe Farman, Brian Gardiner and Jonathan Shanklin reported a large decrease in stratospheric ozone levels over the #Antarctic.

Their research showed that within a decade, the ozone layer had lost one-third of its thickness over the south polar region—what came to be known as the #AntarcticOzoneHole.

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Road to recovery

In March 1985, world leaders met in Austria the Protection of the Ozone Layer and the Vienna convention was signed, calling for more research on the ozone layer.

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Still, it contained no legally binding goals for ODS reductions. However, the ozone hole story caught the attention of the public who feared skin cancer, cataract and many ecological consequences of ozone depletion.

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September 16, the day when Montreal Protocol was signed in 1987, is celebrated as International Day for the Preservation of the Ozone Layer since 1994.

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Now, we have learnt a lot more about the ozone over the past three decades, and know that many parts of the world experience seasonal fluctuation in the ozone layer.

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Every inch of the layer is being tracked regularly now, and the phasing-out of CFCs has helped it’s recovery to a large extent.

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As per the US Environmental Protection Agency estimates, the implementation of the Montreal Protocol could avoid 443 million cases of skin cancer, 2.3 million skin cancer deaths, and 63 million cataracts in the United States alone.

By the mid-21st century, a complete recovery of the ozone layer is expected.

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Link to climate change

Climate change, global warming and ozone depletion are all linked intricately as every change in atmosphere influences each of these phenomena.

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Due to global warming, the temperature of the stratosphere is falling gradually, leading to the formation of more stratospheric clouds over Antarctica, and hence delaying the recovery of the Ozone Hole.

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Moreover, a depleted ozone layer results in increased warming due to higher influx of solar radiation. Also, the substances that deplete ozone possess very high global warming potential, hence leading to increased atmospheric warming.

As humanity recovers a devastating pandemic, the path ahead is to take lessons and inspiration from our battle against ozone depletion and build back a better future.

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(Image credit: N Kanaka / BCCL, Visakhapatnam)