Location of large mystery source of banned ozone depleting substance uncovered

October 26, 2018, University of Bristol

The compound, carbon tetrachloride, contributes to the destruction of the Earth's ozone layer, which protects us from harmful ultraviolet radiation.

As a result, the production of has been banned throughout the world since 2010 for uses that will result in its release to the atmosphere. However, recent studies have shown that global emissions have not declined as expected, with about 40,000 tonnes still being emitted each year.

The origin of these emissions has puzzled researchers for many years.

Alongside collaborators from South Korea, Switzerland, Australia and the USA, researchers at the University of Bristol aimed to quantify emissions from eastern Asia.

To do this, they used ground-based and airborne atmospheric concentration data from near the Korean peninsula and two models that simulate the transport of gases through the atmosphere.

Their results, published in the journal Geophysical Research Letters, show that around half of the 'missing' global emissions of tetrachloride originated from eastern China between 2009 and 2016.

Lead author, Dr. Mark Lunt, from the University of Bristol's School of Chemistry, said: "Our results show that emissions of carbon tetrachloride from the eastern Asia region account for a large proportion of and are significantly larger than some previous studies have suggested.

"Not only that, but despite the phase out of carbon tetrachloride production for emissive use in 2010, we found no evidence for a subsequent decrease in emissions."

In fact, emissions from certain regions may have increased slightly since 2010. The results from the study show the emergence of a new source of emissions from the Shandong province of China after 2012.

Whilst the results of this and earlier studies in Europe and the USA now explain a large part of the global distribution of carbon tetrachloride emissions, there are still large gaps in our knowledge. Furthermore, recent reports have suggested that very large amounts of this gas may be emitted inadvertently during the production of other chemicals such as chlorine.

Dr. Matt Rigby, Reader in Atmospheric Chemistry at the University of Bristol and co-author, said: "Our work shows the location of carbon tetrachloride emissions. However, we don't yet know the processes or industries that are responsible. This is important because we don't know if it is being produced intentionally or inadvertently."

He also added: "There are areas of the world such as India, South America and other parts of Asia, where emissions of ozone-depleting gases may be ongoing, but detailed atmospheric measurements are lacking."

It is hoped that this work can now be used by scientists and regulators to identify the cause of these emissions from eastern Asia. Ultimately, if these emissions can be avoided, it would hasten the recovery of the stratospheric ozone layer.

Dr. Lunt said: "Studies such as this show the importance of continued monitoring of ozone-depleting gases. There is a temptation to see ozone depletion as a problem that has been solved. But the monitoring of man-made ozone-depleting gases in the atmosphere is essential to ensure the continued success of the phase-out of these compounds."

Explore further: Emissions of banned ozone-eating chemical somehow are rising

More information: M. F. Lunt et al, Continued Emissions of the Ozone-Depleting Substance Carbon Tetrachloride From Eastern Asia, Geophysical Research Letters (2018). DOI: 10.1029/2018GL079500

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19 comments

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KelDude
4.9 / 5 (7) Oct 26, 2018
It seems that the Chinese do not think of the consequences of this problem. "Carry on, business as usual" will not save them from getting fried by the UV rays getting through because of the decrease in ozone. As with many of these types of environmental issues, it appears the average Chinese person just doesn't care. Is it because of the total control by big government causes them to think there's nothing they can do so carry on? Or does that government think it's a problem for the rest of the world to worry about? There is a long history of environmental destruction in China as if there are no consequences for them.They need to start looking in their own back yard and take a personal interest in making their environment better. Look at all the smog in Beijing! That didn't blow in from Siberia. Lastly all that crap blows over the rest of the world so we all pay the price with bad air!
rrwillsj
2.8 / 5 (4) Oct 26, 2018
Dude, you are contradicting yourself ignoring that much of the present China pollution has occurred since they switched their economic system to unfettered capitalism.

In exchange for the Party retaining a facade of political. power. Tjey accept the rise of a middle-class competent at developing technology. Including modernizing the PRC military forces.

While turning a blind eye to the surge of plutocrats manipulating the Nation's financial markets.

Since the most obvious influence we, the Western Powers, have to influence China to accept a cosmopolitan modernity? Has been the insidious cultural subversion induced by Disney and other Western entertainment to convert the general Chinese population into passive consumer drones.

As previously accomplished with you and the people around you.

Of course you refuse to believe it. The rejection of the Liberal Arts & Sciences has left all too many people without the intellectual tools to analyze sociak trends. .
carbon_unit
4.7 / 5 (7) Oct 26, 2018
They will not get fried because the rest of the world is acting responsibly, keeping levels down. They are freeloading.
blazh femur
4.3 / 5 (6) Oct 26, 2018
I am shocked - SHOCKED! - that China would do such a thing.
tmariner
4.3 / 5 (3) Oct 26, 2018
China has to grow up -- they no longer can use or need the wide-eyed innocent act of an "emerging nation". It insults how far they have progressed technically and as a country.

They have to become adults and play by a fair set of rules -- they will win anyway because the rest of the world spends all of its time arguing over who gets selected to "lead" and has forgotten the lessons of "One Small Step for Man". China's leader IS an engineer.
Parsec
2.7 / 5 (3) Oct 26, 2018
The headline is quite misleading. The truth is that the location has been narrowed down, not located. It is too soon to determine even if these emissions are deliberate, much less part of some kind of wrong doing.

For example, let's say that industrial production of chlorine for the use in water purification is the culprit and the process involved produces a large byblow of carbon tet. This means that a large amount of the chlorine is being wasted. No one in their right mind would deliberately waste a large percentage of product deliberately. It would cost too much money.

I am not saying that China or any other nation wouldn't be capable of deliberately releasing a large amount of this chemical, but there isn't yet enough data to make such accusations.
Ojorf
3.5 / 5 (11) Oct 27, 2018
They will not get fried because the rest of the world is acting responsibly, keeping levels down. They are freeloading.


Yeah, unlike the USA and their unselfish and total commitment to mitigating AGW?

Da Schneib
3 / 5 (2) Oct 27, 2018
Oh, big surprise, it was China.

So who got paid off?

Just askin'.
Thorium Boy
2.4 / 5 (7) Oct 27, 2018
The Western Left in politics, academia and media are ALWAYS excusing their darling China despite that country being the largest threat to the environment in the World.
szore88
2 / 5 (4) Oct 27, 2018
So Socialism is an utter failure. Who knew?
Da Schneib
4 / 5 (4) Oct 27, 2018
They will not get fried because the rest of the world is acting responsibly, keeping levels down. They are freeloading.


Yeah, unlike the USA and their unselfish and total commitment to mitigating AGW?

My country is currently making a lot of political noise about this which I and many others here are quite upset about. We're working on fixing it, unlike the Chinese.
katesisco
1.7 / 5 (3) Oct 27, 2018
https://www.chemi....article
https://www.epa.g...ride.pdf
China granted exemption to use 65 tons Carbon Tet which means that other productions have not fallen as required.
Carbon disulfide is a known dna disrupter, and exposing methane to thermal conditions produces phosgene so what is actually a danger is the excess of methane and our climate change; we could have a massive wave of deadly gas production with the unintended combination of high heat and methane.
katesisco
1 / 5 (2) Oct 27, 2018
https://www.chemi....article
https://www.epa.g...ride.pdf
China granted exemption to use 65 tons Carbon Tet which means that other productions have not fallen as required.
Carbon disulfide is a known dna disrupter, and exposing methane to thermal conditions produces phosgene so what is actually a danger is the excess of methane and our climate change; we could have a massive wave of deadly gas production with the unintended combination of high heat and methane.
katesisco
1 / 5 (2) Oct 27, 2018
https://www.chemi....article
https://www.epa.g...ride.pdf
China granted exemption to use 65 tons Carbon Tet which means that other productions have not fallen as required.
Carbon disulfide is a known dna disrupter, and exposing methane to thermal conditions produces phosgene so what is actually a danger is the excess of methane and our climate change; we could have a massive wave of deadly gas production with the unintended combination of high heat and methane.
katesisco
1 / 5 (2) Oct 27, 2018
https://www.chemi....article
https://www.epa.g...ride.pdf
China granted exemption to use 65 tons Carbon Tet which means that other productions have not fallen as required.
Carbon disulfide is a known dna disrupter, and exposing methane to thermal conditions produces phosgene so what is actually a danger is the excess of methane and our climate change; we could have a massive wave of deadly gas production with the unintended combination of high heat and methane.
katesisco
1 / 5 (2) Oct 27, 2018
https://www.chemi....article
https://www.epa.g...ride.pdf
China granted exemption to use 65 tons Carbon Tet which means that other productions have not fallen as required.
Carbon disulfide is a known dna disrupter, and exposing methane to thermal conditions produces phosgene so what is actually a danger is the excess of methane and our climate change; we could have a massive wave of deadly gas production with the unintended combination of high heat and methane.
Ojorf
2 / 5 (4) Oct 27, 2018
They will not get fried because the rest of the world is acting responsibly, keeping levels down. They are freeloading.


Yeah, unlike the USA and their unselfish and total commitment to mitigating AGW?

My country is currently making a lot of political noise about this which I and many others here are quite upset about. We're working on fixing it, unlike the Chinese.


Yeah I know. It's Trump. What a disaster. Should never have happened. A series of very unfortunate events.
rrwillsj
2.3 / 5 (3) Oct 27, 2018
Oh poor bag_boy, Whoops! Sorry, I forgot T_M's newest moniker, pony_boy.

If pony_boy had the the strength of character? Hell, any character at all! If he was capable of honestly confronting his innate racist cowardice.

He would admit that the Right Fascism he panders to. Is a mirror-image of the PRC Left Fascist regime. And they need each as fake enemies to mutually prop up their corrupt, doddering systems.

Almost exactly as predicted by E.A. Blair as George Orwell.
24volts
2.3 / 5 (4) Oct 27, 2018
They will not get fried because the rest of the world is acting responsibly, keeping levels down. They are freeloading.


Yeah, unlike the USA and their unselfish and total commitment to mitigating AGW?


The US has done more to reduce pollution than just about any other country on the planet. Why don't you do a little research before you post something and look like a total idiot.

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