A new modeling based paper in Atmospheric Chemistry and Physics takes on that question directly.
Of course the result is another “saved the world” moment according to some:
[ Source: http://twitter.com/AndrewDessler/status/442342191067693056 ]
I certainly don’t have a problem with reducing CFC’s, but Andrew Dessler’s comment speaks to the hero syndrome some of these scientists seem to have, which sometimes results in the “noble cause corruption of science” where the end justifies the means. Here is the paper abstract, link to full text follows.
Abstract.
Ozone depletion by chlorofluorocarbons (CFCs) was first proposed by Molina and Rowland in their 1974 Nature paper. Since that time, the scientific connection between ozone losses and CFCs and other ozone depleting substances (ODSs) has been firmly established with laboratory measurements, atmospheric observations, and modeling studies. This science research led to the implementation of international agreements that largely stopped the production of ODSs. In this study we use a fully-coupled radiationchemical-dynamical model to simulate a future world where ODSs were never regulated and ODS production grew at an annual rate of 3%. In this “world avoided” simulation, 17% of the globally-averaged column ozone is destroyed by 2020, and 67% is destroyed by 2065 in comparison to 1980.
Large ozone depletions in the polar region become yearround rather than just seasonal as is currently observed in the Antarctic ozone hole. Very large temperature decreases are
observed in response to circulation changes and decreased shortwave radiation absorption by ozone. Ozone levels in the tropical lower stratosphere remain constant until about
2053 and then collapse to near zero by 2058 as a result of heterogeneous chemical processes (as currently observed in the Antarctic ozone hole). The tropical cooling that triggers the ozone collapse is caused by an increase of the tropical upwelling. In response to ozone changes, ultraviolet radiation increases, more than doubling the erythemal radiation in the northern summer midlatitudes by 2060.
Full paper: http://t.co/8LRrUDb3Yf
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Ed Zuiderwijk says:
March 9, 2014 at 6:36 am
Google (or in this case, Google Scholar) is your friend.
http://scholar.google.com/scholar?hl=en&as_sdt=0,39&q=measurement+of+cfcs+in+stratosphere
John M, very well said. This chemistry is complex. Ureddera is giving it some good thought but is making it out to be too simplistic. There is nothing fundamental about ozone (or CFC) stability. It all depends on the environment (temp, press, etc.) and collisions with other species. One molecule of ozone in a vacuum would be stable indefinitely. There are hundreds of reaction rates involved in this and this is a case where computer models can do what humans cannot. (That doesn’t necessary make them right of course.) The problem is simplified in that we can think of it as pseudo first-order in CFCs but not in ozone or any of the other photochemically active species involved. These things are changing all over the place, regionally, diurnally, etc.
With regard to OH radical formation from ozone and water, it is NOT a primary reaction, but involves photolysis to O 1D . See below. I would agree with most everyone that this problem is not very well understood, but is certainly less complex than the climate system.
http://www.nature.com/nature/journal/v442/n7099/fig_tab/442145a_F1.html
R Shearer,
Thanks. Oddly enough, I have some support for those who argue that there was an overreaction to the ozone scare. I can recall ridiculous “peer-reviewed” papers involving “frogs under glass” to measure the impact of small changes in UV exposure and hyperbolic claims about blind Argentinian sheep that should have had some journalists dismissed for malpractice. And after all these years, I’m not sure anyone can show the ozone hole is recovering as fast as the proponents of the CFC ban said it would, which I think could mean that they underestimated the complexities of the entire system and perhaps weighted the effect of CFCs over “other” factors too highly. Of course, it could also mean CFCs were even more potent that thought, but the point is, we still don’t know.
And getting back to the topic of this post, I am hard pressed to see what long-term damage waiting 5 or 10 years would have done, other than some CFC replacement patents would have lost some value. 🙂
But having said all that, if we can at least get folks to stop saying silly stuff like “everyone knows CFCs are too heavy to make it to the stratosphere” or “a catalyst can’t have an effect on a fast reaction”, it will have been a good weekend.
John M said:
“ozone formation and destruction are both occurring in the tropics and at the poles. It’s not the reaction rate of a single reaction that’s important, it’s the balance of the two. Just because Dobson’s theory is old doesn’t mean the two reactions can’t be impacted differently by CFCs and catalytic reactions in the two regions.”
Exactly.
But consider the two reactions (ozone creation and ozone destruction) being impacted differently at the tropics and the poles as a result of variations in solar activity.
That has the potential to produce the observed climate zone and jet stream changes.
That fits with the multitude of papers proposing a top down solar effect on the global air circulation.
That fits with the now well recognised change in global atmospheric circulation that has been developing since around 2000 when the previous poleward / zonal drift of the jets and climate zones went into reverse just as we saw the decline from active solar cycle 23 to inactive solar cycle 24.
John M, March 9, 2014 at 7:18 am. Assuming AODS-hypothesis is valid, articles about stratospheric chlorine load are more convincing than those reporting it’s CFC content. The reason is that CFC molecules are inert, but in accordance with AODS-hypothesis they are dissociated. If they are dissociated, how can they be analyzed and reported as molecules with their CFC codes? And wouldn’t the dissociation deplete the stratospheric CFCs?
Apart from that, it seems logical that the biggest enemy of an ozone molecule is another highly reactive molecule, like another ozone molecule.
Brant Ra The reason this work was not well known is the people in the Ivory towers certainly did not want to hear that. After all they cannot have data destroy our their nice ideas and models.
A little logic goes a long way: look at an image of the ozone hole defined as depletion to below
220 Dobson units. http://ozonewatch.gsfc.nasa.gov/facts/hole_SH.html
Now look at the “collar” of high ozone encircling the “hole”. This shows that the ozone “depleted” over Antarctica is, in fact, just pushed beyond the edge of the hole thereby thickening the ozone in a ring, like a turtleneck sweater. Surely, if we calculate the volume of ozone in the collar we could see if it can be distributed over the hole demonstrating how much, if any, ozone has been actually lost. This collar is what gave me the idea that its diamagnetic character caused it to be pushed away from the “hole” (along with all other atmospheric gases EXCEPT O2 OXYGEN WHICH IS COMPARATIVELY STRONGLY MAGNETIC – illustrated in my post above:
Gary Pearse says:
March 8, 2014 at 5:16 pm
Anyone, please offer an alternative to magnetics for causing a concentration of ozone in a collar around the ozone hole. If you appeal to winds, please still explain the concentration in the collar and how it shows that ozone has been destroyed.
@Stephen Fisher Wilde
I am sure you are on the right track!
I did some analysis of ozone data from a station in the Alps, somewhere in Switzerland. They had data going back to the 1920s. I remember pinpointing the date when ozone starting decreasing as being around 1951. The ozone concentration started increasing again in 1995. This was established from the bending points in the polynomial that fitted best to the actual data.
The 1995 date came also up when looking at more recent data from a station in the SH.
These dates are significant when you compare them with my best fit for the drop in the speed of warming when looking at maximum temperatures.
http://blogs.24.com/henryp/2012/10/02/best-sine-wave-fit-for-the-drop-in-global-maximum-temperatures/
“I have seen this happen before, of course. We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”
-James Lovelock
http://www.theguardian.com/environment/blog/2010/mar/29/james-lovelock/print
I’m surprised nobody in the MSM has picked this up. Guess they would have if Lovelock had worked for big tobacco.
Jaakko Kateenkorva says:
March 9, 2014 at 8:48 am
Not sure what you’re getting at here. Are you saying that we can’t measure chlorine radicals in the stratasphere and since we can’t measure them they can’t be there?
Anyway, they can be measured.
http://onlinelibrary.wiley.com/doi/10.1029/94GL02781/abstract;jsessionid=D3C9FE7FCC92E2990B4026D24A892D2C.f03t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false
Are you saying it’s all or nothing? Either they are completely dissociated or not dissociated at all?
Nobody’s saying they have an infinite lifetime
As has been pointed out, the reaction chemistry is complex with many competing reactions. The ice crystal/halide mechanism is thought to enhance the net destruction of ozone at the poles relative to what happens in thei absence of CFCs. There is no “all or nothing” in atmospheric chemistry. It’s not unusual to have competing reactions, each with their own mechanisms and each impacted by different catalytic chemistry.
They are already lining up the new excuses just in case the CFC ban does not close the Ozone hole. News just in today from the BBC.
http://dx.doi.org/10.1038/ngeo2109
R. Shearer says:
March 8, 2014 at 4:06 pm
“Sweet Old Bob, if the wind and lift is strong enough, it doesn’t matter if the kite has a string or not. Without the string, it might not be held to the ground at all.”
And, if my grandmother had wheels, she’d be a wagon. How do you get the lift? By enforcing a consistent angle of attack on the kite via the tension in the string. When the string breaks, does the kite continue flying upward? Perhaps briefly and randomly, but not for very long.
Were that not the case… Do you have any idea how many kite strings break per year? By now, the poles should be swarming with errant kites built up over centuries of distressed kite-flyers, if your analogy had any validity. We’d need an international kite-flying protocol to phase out kites.
Bad analogy. Find another one.
John M says:
March 9, 2014 at 10:20 am
Do you have any non-paywalled resource which discusses stratospheric ClO over time since the phase-out? Given that there is apparently no conclusive evidence that the phase-out has done any good, I would expect, if the threat is significant as claimed, that stratospheric ClO basically would show little decline over the interval.
This seems to suggest that either A) ClO is declining, but its effect on the ozone layer was dramatically exaggerated, or B) ClO is not declining, and the protocol has been unsuccessful.
Is there a third option which I am not considering? Either of these suggest that the phase-out is either futile, or ineffectual, neither of which is very confidence-inspiring.
Bart,
Here’s one that’s available.
http://www.atmos-chem-phys.net/11/5321/2011/acp-11-5321-2011.pdf
As I said above, it appears that ozone recovery is not as “robust” as proponents of the ban indicated it would be. I don’t know why, and I’ve got no quarrel with those who think things don’t quite add up. In my own mind, I don’t know if the sluggish recovery argues for or against the ban, but I do have a hard time convincing myself that waiting a few years would have been disastrous.
All I ask is that people recognize the difference between thoughtful skepticism and raving cynicism.
Kramer,
One would presume that Lovelock doesn’t include his own work in that category.
“In 1974 I made the first measurements of the CFCs and carbon tetrachloride in the stratosphere and showed them to be declining there as the ozone depletion theory required.”
http://www.jameslovelock.org/page3.html
John M says:
March 9, 2014 at 2:20 pm
Thanks, John. My mind is open on the question. I try not to react strongly one way or the other until I have evidence. E.g., my suggestion to R. Shearer above is merely to find a better analogy than kites. But, I am not dismissing the possibility, even high probability, that some chlorine ions for which we are responsible get transported to the upper reaches of the atmosphere. The question in my mind is, in what measure?
That the ions are there appears to be irrefutable. How did they get there, if not transported from the surface? I cannot provide any other answer, and I know of no other available mechanism. But, are all, or even most, of the ions generated at the surface a result of our activities? Do we actually know the ratio of human to natural inputs?
I am entirely open to the possibility that the the CFC ban was necessary. There just does not appear yet to be any evidence that it helped. So, I wonder just how much of that ClO concentration was being driven by us? It would be nice to see an estimate of human production rates, which we could compare to the concentration curves to see how well they correlate, if anything like that is available.
Then, of course, there is the question of whether ClO levels make much difference on ozone levels anyway. However, given what a caustic substance chlorine is, I can well see a reasonable justification for erring on the side of caution.
Vis a vis the relationship to the climate debate, that is the key consideration which divorces the two entirely in my mind. CO2 is, after all, the stuff of life itself.
Dupont funded the study that claimed that CFCs were destroying the ozone layer. Dupont then funded the hype to demonize the main CFC which was theirs, out of patent, and becoming cheap around the world. So, it was banned around the world and people could not afford the new refrigerant and people died.
Dupont just happened to have a replacement, much more expensive replacement already under patent and ready to go.
Now, 20 years later, with that new refrigerant out of patent, they admit that the CFC-demonizing science was bogus and that actually it is nitrogen gas in the atmosphere interacting with solar radiation that eats the ozone. It has nothing to do with CFCs, nada, zilch.
Mike T, I doubt your consensus that Polar bears get skin cancer. Dogs and cats do get cancer on the skin, but generally not caused by the holes in ozone layer. If they get sunburned sure it affects them, especially the short haired or bald haired breeds. Anyway, I lived in Sydney, and the beaches there are packed during the summer with lots of tourists who do not realise how strong our sun is. I had lived in Cyprus and got very badly sunburned once, so I was very cautious.
Anyway the argument was about the ozone layer, not polar bears, as the ozone layer over the arctic I believe has closed up now.
Bushbunny, it’s an opinion, not a “consensus”. I doubt many wild animals live long enough to die from cancer, skin or otherwise, because if a prey animal they’d slow down and be eaten, if a predator, they’d become unable to hunt. Even in humans, cancer has become a “modern disease” because we live long enough to die from them. None of this stops wild animals from developing skin cancers, or other cancers, in theory, in practice they don’t usually live long enough (it would be worthwhile looking at statistics for animals in zoos, perhaps). Pets have their prey presented every day in a bowl, so live much longer than their wild counterparts, plus they are selected for traits which may predispose them to skin cancer (eg ginger cats, birds with genes connected with albinism).
As for the ozone “hole” affecting Australia, I suggested that Tasmania would be the state most affected by the thinning, and any increase in harmful UV rays reaching the surface. The brouhaha has had at least one positive side effect- and that’s sun awareness. I’m pretty old, and many of my skin cancers are in part due to exposure as a youngster- when suncreen, apart from white/pink zinc paste, hadn’t been invented. That was in Sydney- but almost anywhere on the mainland in summer is dangerous, with or without stratospheric ozone depletion. Tasmania, probably more so, on the rare hot days because the population would shed their warm clothing and the UV indices are very high. I now live in an area frequented by “backpackers” mostly from Europe and they allow themselves to be burned black in some cases. Europeans seem to worship the sun, and get as much as they can when it’s around for the winter when they will hardly see the sun and be rugged up solidly against the cold.
@Dennis Hand:
“a chlorine ion Cl¬–– would only weigh 17 amu’s, much lighter than that of a CFC molecule and therefore more easily transported to the upper atmosphere.”
I believe it was going to be regulated through OSHA back in the 90’s attempted to highly regulate chlorine use for public use such as swimming pools and washing machines.
For swimming pools they attempted to pass legislation to wear a full chimerical suit gloves and full face-mask when poring chlorine into the swimming pool.
chlorine is a widely used chimerical for many products. Lobbying groups from many corporations and organizations was able to stop the bill from passing in California and many other states.
A quick Google search I see they have pass something that must of been a weaker law then what was proposed in the 90’s:
http://www.educatingwellness.com/natural-health/dangers-of-bleach/
higley7 says: “actually it is nitrogen gas in the atmosphere interacting with solar radiation that eats the ozone.”
OH! i think you hit on something they can ban Nitrogen in car tiers, Liquid Nitrogen and everything else based on Nitrogen! I bet the public would buy it to!
DDT is another fake science that was eliminated though it’s ended up killing millions of people.
The belief in the flat earth was easy to pass off as real just as it is today.
Glaciation is coming sooner or latter and no one is even disguising a to do list for when it takes place. I can see an easy billion people dieing when it does hit.
John M says: March 9, 2014 at 10:20 am
“Are you saying it’s all or nothing? Either they are completely dissociated or not dissociated at all?”
No. I’m writing that the AODS-hypothesis contains too many assumptions, paradoxes and assertions to be plausible in my opinion. Many have already been discussed. Only to note a few:
The CFC can either be assumed accumulating (and measurable in molecular form) or ozone dissociates significantly to deplete ozone in stratosphere (and we can no longer assert the source of the ions). I don’t see how it could convincingly do both at the same time. During a discussion of an ozone layer in the layer called stratosphere, the assertion of atmosphere as a homogenous entity also seem a bit misguided.
The AODS-hypothesis bears many signs of being upscaled from laboratory to earth without the use of Occam’s razor, let alone proof. You seem to agree somewhat, but from high. There are others with academic degree in natural sciences and decades of experience, only perhaps different than yours.
Dennis Hand
“Being we are talking about the effect of a Cl–– ion, why has no one addressed the issue of the chlorine that evaporates into the atmosphere regularly from the chlorination of water systems, swimming pools, hot tubs, and other uses of chlorine.”
It is not chloride ion (Cl-) or chlorine molecule (Cl2) that reacts with ozone. It is chlorine atom (Cl). CFC breaks down into chlorine atoms. The chlorine in your swimming pool is Cl2. The one in seawater is Cl-.
Dessler has been sniffing the hydrocarbons again … he already has brain damage.
Back in ’93 I read a comment from the British Antarctic Survey which mentioned Mt Erubus. They sampled the volcano’s gases and estimated that several tonnes of hot chlorine were coming out per day during the time they were there. If this is correct, it would be reasonable to assume that much of the Cl found in the stratosphere came from the volcano as it had been actively erupting for some time. Does anyone have real info on this?