2012 Antarctic Ozone Improvement

[Backtrack]

In 2012, the hole in the ozone layer over Antarctica was smaller than it has ever been in the last decade.

This is great news. Ozone, while a pollutant at lower altitudes, is concentrated in a particular layer of the stratosphere; around 20-30 kilometres above the surface of the Earth- here, this layer of ozone prevents the harmful ultraviolet light from the sun reaching the surface.

The hole in the ozone layer has been a product of human interaction with the natural environment. The development of chlorofluorocarbons (CFCs) in the 1930s, which were used in most aerosols and refrigeration units lead to the loss of ozone over Antarctica by as much as 70%.

How did CFC’s contribute to ozone loss you might ask?

At tropospheric levels, CFC molecules are actually almost completely inert; both chemically and biologically- unfortunately, because of this inability to react, the molecules are able to escape into the stratosphere, where the fun begins. At these higher altitudes, CFC’s are able to undergo photolytic decomposition as a consequence of being exposed to an intense flux of energetic ultraviolet radiation. It is here that the molecule is broken down, for example CFC-11 which contains three chlorine atoms breaks down as follows:

CFCl3 + hv --> *CFCl2 + *Cl

It is the release of this chlorine free radical that leads to the demise of ozone, we can see this in the equation:

*Cl+O3 --> ClO* + O2.

and furthermore..

ClO* +O --> *Cl + O2 and so on.. etc.

As a result of this destruction of our natural protective barrier, the Montreal Protocol was established in 1987, which put limits and bans on the use of CFC’s. This protocol is often viewed as the single most successful international environmental agreement to date. This is probably an exaggeration- there are many flaws in the protocol, but alas, we have achieved monumental heights by changing our ways and now slowly our ozone layer is starting to recover.

In many ways it is very important to see the Montreal Protocol as a success, and more importantly, to see that we can in fact change our ways and protect our environment.

Edited February 13, 2013 by Backtrack

[Gray-Wolf]

There is an important observation missing from the account above and that has been the impact of the Circumpoar winds/current over the lifetime of the hole.

The impacts from the hole strengthened the winds that blow around the southern oceans and drive the ocean circulation around the Antarctic continent. This incease in current and wind speed has effectively kept most of Antarctica in a kind of 'splendid Isolation' from the changes that the rest of the globe has experienced over that time.

We now face the healing of the Ozone layer reducing those surface impacts and allowing those 'changes' into the last place on Earth not to see the scale of impacts that the rest of the globe has seen.

Remember, the poles face a much faster warming process than places closer to the equator (as we have seen in the Arctic).

The Antarctic Peninsula pokes through the circumpolars and has seen some of the highest warming seen on the planet. I do not look forward to that level of change entering into the rest of the continent.

It is kind of like another of man's polluting impacts that has ,in fact, saved us from the worst of the warming we have built into the system (Global Dimming).

Like the repairing ozone our 'cleaning up' of the pollution will also allow the full impacts of our pollution to be felt.

Sorry to put such a downer on things but there it is (as I see it)!

[Backtrack]

Interesting stuff GW, I think I'll read more into climate change over the poles as it's clearly a very interesting subject!

The above was taken from a science group on Facebook which I like: http://www.facebook.com/IFeakingLoveScience?fref=ts

Has over 3 million likes, something that always provides an interesting read for me!

Very interesting place Antarctica, can't wait to learn more about it. Can only be good news that the ozone is healing though?

[Gray-Wolf]

I'm sure for the folk worst impacted by the hole (Australia/southern tip of S.America) it is a very good sign but for the folk who use Antarctica as a sign that ADW is not real then a very bad thing.

You will have noted that since the Arctic did not rebound/recover as some had promised all eyes had turned south. With the lessening of the hole's impacts then the sudden upsurge in warming we should expect will leave them very little to crow over (snowfall in winter?).

Of course any upsurge in melt will be of grave concern to us all.

Thanks for the link b,t,w. I'll check it out!