NASA research shows Earth’s atmosphere contains an unexpectedly large amount of an ozone-depleting compound from an unknown source decades after the compound was banned worldwide.
Carbon tetrachloride (CCl4), which was once used in applications such as dry cleaning and as a fire-extinguishing agent, was regulated in 1987 under the Montreal Protocol along with other chlorofluorocarbons that destroy ozone and contribute to the ozone hole over Antarctica. Parties to the Montreal Protocol reported zero new CCl4 emissions between 2007-2012.
However, the new research shows worldwide emissions of CCl4 average 39 kilotons per year, approximately 30 percent of peak emissions prior to the international treaty going into effect.
“We are not supposed to be seeing this at all,” said Qing Liang, an atmospheric scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study. “It is now apparent there are either unidentified industrial leakages, large emissions from contaminated sites, or unknown CCl4 sources.”
NASA video discusses new research that shows Earth’s atmosphere contains an unexpectedly large amount of an ozone-depleting compound from an unknown source decades after the compound was banned worldwide.
As of 2008, CCl4 accounted for about 11 percent of chlorine available for ozone depletion, which is not enough to alter the decreasing trend of ozone-depleting substances. Still, scientists and regulators want to know the source of the unexplained emissions.
For almost a decade, scientists have debated why the observed levels of CCl4 in the atmosphere have declined slower than expectations, which are based on what is known about how the compound is destroyed by solar radiation and other natural processes.
“Is there a physical CCl4 loss process we don’t understand, or are there emission sources that go unreported or are not identified?” Liang said.
With zero CCl4 emissions reported between 2007-2012, atmospheric concentrations of the compound should have declined at an expected rate of 4 percent per year. Observations from the ground showed atmospheric concentrations were only declining by 1 percent per year.
To investigate the discrepancy, Liang and colleagues used NASA’s 3-D GEOS Chemistry Climate Model and data from global networks of ground-based observations. The CCl4 measurements used in the study were made by scientists at the National Oceanic and Atmospheric Administration’s (NOAA’s) Earth System Research Laboratory and NOAA’s Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder.
Model simulations of global atmospheric chemistry and the losses of CCl4 due to interactions with soil and the oceans pointed to an unidentified ongoing current source of CCl4. The results produced the first quantitative estimate of average global CCl4 emissions from 2000-2012.
In addition to unexplained sources of CCl4, the model results showed the chemical stays in the atmosphere 40 percent longer than previously thought. The research was published online in the Aug. 18 issue of Geophysical Research Letters.
“People believe the emissions of ozone-depleting substances have stopped because of the Montreal Protocol,” said Paul Newman, chief scientist for atmospheres at NASA’s Goddard Space Flight Center, and a co-author of the study. “Unfortunately, there is still a major source of CCl4 out in the world.”
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Here’s Wikipedia’s interesting article on the substance:
http://en.wikipedia.org/wiki/Carbon_tetrachloride
“CCl4 is still made by China, India and others. No surprise that they are finding the stuff in the air.”
I thought exactly the same thing and did a Google search using the keywords carbon tetrachloride and China. What they report as produced and used probably bears no connection with reality, just as their GDP figures don’t.
“NASA admits they do not know. That should be the headlines. It makes one wonder how much else they do not know..”
With 33 (and counting) excuses for the “pause” given, it’s apparently quite a lot.
There will always be an ‘ozone hole’ in the Antarctic. Ozone is an unstable substance: the ozone produced by the summer sun breaks down into oxygen during the long sunless winter months. The half life of ozone in air at -50C is 3 months, at -35C the half life is 18 days. All this talk of CFCs and carbon tet is just scientist trying to find work for themselves.
mjc says:
August 21, 2014 at 6:28 am
PeterB in Indianapolis says:
August 21, 2014 at 5:47 am
Problem is, there is no way of getting the “bad” ozone in the lower levels of the atmosphere up to the upper levels of the atmosphere where the “good” ozone is.
Then just how does the 3x heavier CCl4 get up there?
Turbulent transport and mixing.
I never could get my head around the fact that these heavier ‘ozone depleters’ made their way to the upper atmosphere, while the much lighter ozone that was also a ‘pollutant’ hugged the ground and never moved. Never mind the fact that the ‘depleters’ don’t ever seem to ‘work’ anywhere except the upper atmosphere (or the lab).
The ‘depleters’ like freons and carbon tet are inert in the lower atmosphere, however once they reach the stratosphere they encounter UV light which causes them to slowly break down forming Chlorine atoms which are very reactive and react with O3. The reactions cause destruction of the ozone but the Cl gets regenerated and so a single Cl can destroy as many as 1000 O3 molecules.
Ozone is an extremely reactive species but there’s no reason why it couldn’t be transported to the stratosphere from the surface, it just won’t make it there intact because it will collide with (and react with) so many other molecules on the way. Typically when the sun rises the reactions start and ozone and photochemical smog are formed, the concentration peaks around noon and after sunset all the O3 is depleted, not enough time for it to make it to the stratosphere.
Gee, its made with methane and chlorine two abundant substances in the atmosphere and oceans.
CH4 + 4 Cl2 → CCl4 + 4 HCl
The reaction produces first a hydrogenated chlorides and in excess chlorine, eventually all the “H” reacts to produce carbon tet.
CH4 + Cl2 =>CH3Cl + HCl
CH3Cl + Cl2 =>CH2Cl2 + HCl
CH2Cl2 + Cl2=>CHCl3 + HCl
CHCl3 + Cl2 =>CCl4 + HCl
To support this simple ‘model’, there is measurable HCl in the atmosphere, too. This all reeks of NASA’s perplexion over the stubborn ozone hole that is not going away (it waxes and wanes) according to their models. There is a lot of chemistry going on in and on our planet that we don’t yet know about, but this simple reaction should be the first thing they thought about. But then, if they did, they would be raising alarm about the 1.7ppm methane in the atmosphere causing the ultimate destruction of the Ozone sphere. With the abundance of Cl2 in the atmosphere, it is no wonder that methane is so low. If my idea is correct, methane will never be more than a couple of ppm in the atmosphere. One day you will read all about it.
Barrie Sellers says:
August 21, 2014 at 7:20 am
There will always be an ‘ozone hole’ in the Antarctic. Ozone is an unstable substance: the ozone produced by the summer sun breaks down into oxygen during the long sunless winter months.
You have this backwards, the ozone is preserved during the winter, it is in the spring and summer when the UV light from the sun initiates the destruction of the ozone.
Paul Drahn says:
August 20, 2014 at 3:49 pm
Paul, you pegged it about right, There are probably thousands (single digit thousands) of these extinguishers still around, but I doubt even a thousand of them still have carbon tet in them. And if every one of the several thousand remaining has 5 pounds of carbon tet in them (unlikely) that amounts to a few tons of carbon tet. That article says something like 39 kilotons of carbon tet is being released every year. Sources like this don’t have a hope of explaining the “unexpected” source.
I vote for China.
After all, what’s a little ‘carbon tet’ released into the atmosphere compared to adding melamine to milk and baby formula?
(This based entirely on my ‘gut feeling’, with no basis in fact or information whatsoever.)
The CFC scare was a red herring as was the CO2 scare.
There is no human influence on the climate. There never was.
All climate change is natural
http://blogs.24.com/henryp/2013/02/21/henrys-pool-tables-on-global-warmingcooling/
Well, there are always been a seasonal “hole” in the ozone-rich layer of polar regions, particularly antarctic because of the strong southerm polar vortex, insulating atmosphere there from the tropical atmosphere during night time (that is months-long night). This has nothing to do with CCl4. The chemical reaction on which this propaganda is based has never been observed in nature either.
A quick reminder : stratospheric ozone does not protect from the UV, it is merely a byproduct of the absorption of the UV in upper atmosphere by the oxygen there, a very tiny byproduct, very unstable, which exists only because there is UV light reaching the area, breaking down O2 molecules. That is, no oxygen in the atmosphere, no ozone creation process. During winter months, it’s dark over the pole, and that unstable ozone dies out, naturally. Comes the sunrise, october, the polar vortex weakens, and in a matter of days, ozone-rich atmosphere is homogenized again.
The entire ozone scare was set up and maintained by precisely the same crew that is now running the global warming scam, for the same reason. Check the IPCC origine, it has nothing to do with science. You can wager that by the time the global warming scam has been abandoned, another technology-blaming cult run by these same people will have begun.
true
it seems people always need a scapegoat, whether real or imigined
however, it could turn out more sinister [eventually]
like Hitler blaming the jews for everything that was wrong in society.
Phil. says:
August 21, 2014 at 8:03 am
Turbulent transport and mixing.
Fine, but that should work for all gasses…not just the ‘bad’ ones. And most claim that the man-made ‘bad guys’ get up there, but the ‘good stuff’ doesn’t.
The ‘depleters’ like freons and carbon tet are inert in the lower atmosphere, however once they reach the stratosphere they encounter UV light which causes them to slowly break down forming Chlorine atoms which are very reactive and react with O3.
And there’s no UV down low?
We are constantly being told that UV is going to kill us…and last I checked, I’m not living in the stratosphere.
No. Both ‘theories’ have problems in that they are incomplete. If mixing occurs THEN it has to apply to all gasses not just a select few. Also, UV in the lesser in amount will still have the same properties and the same abilites as it does in the upper.
Now talking about there being MORE at ground level and the EXCESS, that isn’t afftected by the lower amount of UV being transported by turbulent mixing passes a bit better. But the all ‘bad’/no ‘good’ model does not pass the ‘smell test’…especially given the fact that we are talking about chemistry and not alchemy.
“To investigate the discrepancy, Liang and colleagues used NASA’s 3-D GEOS Chemistry Climate Model and data from global networks of ground-based observations.” Yet again there must be something wrong with reality as the model disagrees with observations.
I weep.
Mixing does apply to all gases. However, we must also consider chemical reactions.
Quick chemistry question. What is the color of solid and liquid oxygen?
re cdquarles I think the answer is blue.
re CCl4 and the ozone layer: the latter seems to have ‘healed’ itself anyway if it was ever ‘sick’ in the first place, but just how much has that caper cost humanity?
The ozone layer is healing, but not on its own. Rather it’s entirely as a consequence of the Montreal Protocol, in the US signed by President Reagan and ratified by the Senate, which phased out production of the Chlorine bearing chemicals which caused it — primarily CCL4, CFCs & HCFCs (the primary bad actors) and a few others.
The industry I worked in during my career – Refrigeration and Air Conditioning, was the primary Global user of CFCs and HCFCs– and the phase-out was costly, but in retrospect worth it, not just because of the environmental benefits in reducing human skin cancer (see the EPA website for quantification, if you want numbers) , but in terms of the superior replacements for HCFCs that were developed by DuPont and other chemical firms. As a result of the industry transitioning to new fluids without chlorine –HFCs — air conditioners gained efficiency, and the stratospheric ozone depletion issue was resolved.
That ‘caper’ was fully supported by the U.S. A/C and Refrigeration Industry, which voluntarily phased out CFCs one year earlier than required by law.
The ‘end of the world’-prophets are nothing new. Especially the variety living off accusing others for the predicted doom.
CH4 + 4 Cl2 → CCl4 + 4 HCl
Golly, that takes a huge factory and some REALLY hard to get chemicals doesn’t it?
I mean you can even electrolyse the HCl and get the chlorine back afterwards..
“””””…..Phil. says:
August 21, 2014 at 8:03 am
mjc says:
August 21, 2014 at 6:28 am
PeterB in Indianapolis says:
August 21, 2014 at 5:47 am
Problem is, there is no way of getting the “bad” ozone in the lower levels of the atmosphere up to the upper levels of the atmosphere where the “good” ozone is.
Then just how does the 3x heavier CCl4 get up there?
Turbulent transport and mixing……”””””
Phil; this must seem like a totally dumb question, since IANACh , but it always puzzles me.
I understand the concept of Chloro-Fluoro-Carbons, eg. “Freons” being rather chemically stable, so they are capable of surviving, long enough, to eventually transport to the Stratospheric levels where uber-UV finally breaks them down, to free the Chlorine.
But here’s my puzzle. I would have thought that Fluorine would be hell on wheels, compared to Chlorine, when it comes to busting up Ozone. So why is it the Chlorine, and not the Fluorine, that is the bad guy, in the Ozone extermination caper ??
mjc August 21, 2014 at 10:38 am
Phil. says:
August 21, 2014 at 8:03 am
Turbulent transport and mixing.
Fine, but that should work for all gasses…not just the ‘bad’ ones. And most claim that the man-made ‘bad guys’ get up there, but the ‘good stuff’ doesn’t.
The ‘depleters’ like freons and carbon tet are inert in the lower atmosphere, however once they reach the stratosphere they encounter UV light which causes them to slowly break down forming Chlorine atoms which are very reactive and react with O3.
And there’s no UV down low?
We are constantly being told that UV is going to kill us…and last I checked, I’m not living in the stratosphere.
The wavelengths needed to photolyze the freons are less than 220 nm, they do not make it past the oxygen through to the troposphere.
No. Both ‘theories’ have problems in that they are incomplete. If mixing occurs THEN it has to apply to all gasses not just a select few. Also, UV in the lesser in amount will still have the same properties and the same abilites as it does in the upper.
All gases are subject to turbulent mixing, those that are reactive or condense out at lower temperatures (e.g. water) won’t make it. The UV is filtered by the O2 and O3 in the stratosphere any that reaches the troposphere does not have the same properties as the original spectrum at the top of the atmosphere.
Now talking about there being MORE at ground level and the EXCESS, that isn’t afftected by the lower amount of UV being transported by turbulent mixing passes a bit better. But the all ‘bad’/no ‘good’ model does not pass the ‘smell test’…especially given the fact that we are talking about chemistry and not alchemy.
Precisely, it’s chemistry there is no such thing as the ‘all bad/no good’ model.
george e. smith August 23, 2014 at 4:40 pm
Phil; this must seem like a totally dumb question, since IANACh , but it always puzzles me.
I understand the concept of Chloro-Fluoro-Carbons, eg. “Freons” being rather chemically stable, so they are capable of surviving, long enough, to eventually transport to the Stratospheric levels where uber-UV finally breaks them down, to free the Chlorine.
But here’s my puzzle. I would have thought that Fluorine would be hell on wheels, compared to Chlorine, when it comes to busting up Ozone. So why is it the Chlorine, and not the Fluorine, that is the bad guy, in the Ozone extermination caper ??
Not a dumb question at all George.
The answer lies in the relative stability of the ‘reservoir’ species that store the released halogens in the stratosphere and allow them to be regenerated after reacting with O3.
In the case of Cl they are HCl and ClONO2 and for Br HBr and BrONO2, these are weakly bound and so readily generate the reactive intermediates that destroy the O3. F however rapidly forms HF which is strongly bound and therefore sequesters the F and prevents the regeneration of the active intermediates.
So the effectiveness of the halogens is in the order I, Br, Cl, F: I compounds are too unstable to make it to the stratosphere, Br is about 40 times more effective than Cl which in turn is thousands of times more effective than F.
Hope that helps George.
Carbon tetrachloride is produced by decaying corpses: “When comparing human decompositional events with animal subsets (pig, deer, dog, cat, squirrel and sheep), carbon tetrachloride, pentane, decane and undecane appear to be human specific, the latter two only when evaluating skeletonized remains.” Vass, Arpad A.: Odor mortis. Forensic Science International. Volume 222, Issues 1–3, 10 October 2012, Pages 234–241. Elsevier.