From the Massachusetts Institute of Technology
Plugging an ozone hole
MIT researchers find that the extremes in Antarctic ozone holes have not been matched in the Arctic
CAMBRIDGE, Mass– Since the discovery of the Antarctic ozone hole, scientists, policymakers, and the public have wondered whether we might someday see a similarly extreme depletion of ozone over the Arctic.
But a new MIT study finds some cause for optimism: Ozone levels in the Arctic haven’t yet sunk to the extreme lows seen in Antarctica, in part because international efforts to limit ozone-depleting chemicals have been successful.
“While there is certainly some depletion of Arctic ozone, the extremes of Antarctica so far are very different from what we find in the Arctic, even in the coldest years,” says Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT, and lead author of a paper published this week in the Proceedings of the National Academy of Sciences.
Frigid temperatures can spur ozone loss because they create prime conditions for the formation of polar stratospheric clouds. When sunlight hits these clouds, it sparks a reaction between chlorine from chlorofluorocarbons (CFCs), human-made chemicals once used for refrigerants, foam blowing, and other applications — ultimately destroying ozone.
“A success story of science and policy”
After the ozone-attacking properties of CFCs were discovered in the 1980s, countries across the world agreed to phase out their use as part of the 1987 Montreal Protocol treaty. While CFCs are no longer in use, those emitted years ago remain in the atmosphere. As a result, atmospheric concentrations have peaked and are now slowly declining, but it will be several decades before CFCs are totally eliminated from the environment — meaning there is still some risk of ozone depletion caused by CFCs.
“It’s really a success story of science and policy, where the right things were done just in time to avoid broader environmental damage,” says Solomon, who made some of the first measurements in Antarctica that pointed toward CFCs as the primary cause of the ozone hole.
To obtain their findings, the researchers used balloon and satellite data from the heart of the ozone layer over both polar regions. They found that Arctic ozone levels did drop significantly during an extended period of unusual cold in the spring of 2011. While this dip did depress ozone levels, the decrease was nowhere near as drastic as the nearly complete loss of ozone in the heart of the layer seen in many years in Antarctica.
The MIT team’s work also helps to show chemical reasons for the differences, demonstrating that ozone loss in Antarctica is closely associated with reduced levels of nitric acid in air that is colder than that in the Arctic.
“We’ll continue to have cold years with extreme Antarctic ozone holes for a long time to come,” Solomon says. “We can’t be sure that there will never be extreme Arctic ozone losses in an unusually cold future year, but so far, so good — and that’s good news.”
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“Ozone levels in the Arctic haven’t yet sunk to the extreme lows seen in Antarctica, in part because international efforts to limit ozone-depleting chemicals have been successful.”
—
So why haven’t efforts to limit ozone-depleting chemicals in the southern hemisphere been as successful?
Louis says:
April 15, 2014 at 3:09 pm
““Ozone levels in the Arctic haven’t yet sunk to the extreme lows seen in Antarctica, in part because international efforts to limit ozone-depleting chemicals have been successful.”
—
So why haven’t efforts to limit ozone-depleting chemicals in the southern hemisphere been as successful?”
For the same reason that Global Warming makes sea ice around Antarctica grow, not shrink.
Note: “They found that Arctic ozone levels did drop significantly during an extended period of unusual cold in the spring of 2011.”
If it is warm, it is the “new normal”. If it is cold, it is “unusual”.
Self-reinforcing thinking.
Please remind me, what was the problem with reduced ozone in the atmosphere? If it was only a theoretical/modeled hazard, today I would be strongly against believing a word these guys were saying. Show me the data.
More ‘only our science can save mankind’ – BULLDUST
For all we know, the ozone hole over Antarctica has been there for decades, centuries, millenia, or longer. When we first went looking for it, it was there. I have seen nothing that conclusively shows that it was caused by CFC’s. There is also evidence that CFC’s don’t destroy ozone anywhere near as much as was feared (the temperature regime is wrong for the reaction).
Good question Louis
Can someone please explain how we know that the ozone hole came from “depletion” and if we could visualize the ozone hole in the past in the same way that we can today? I understand that CFC’s and other chlorines react and degrade ozone, but what is the confidence level that the ozone was a continuous layer before we could visualize it?
CFC’s way to heavy to get above troposphere, Ozone probably blasted during all those above ground nuke tests for 30 odd yrs. The international ban on above ground nuke testing more likely a healing factor …. nice when things work.
The reason isn’t due to man’s banning of a few chemicals. It is due to the Sun’s reduced activity.
When there’s sunlight, ultra-violet rays create Ozone. Ozone is unstable, and quickly breaks down. Those long Arctic and Antarctic winters give the Ozone plenty of time to break down naturally, without being replenished by more sunlight created Ozone.
I suppose REAL global warming, with temperatures as high in the Arctic as in the lower latitudes, there would NEVER be an Ozone hole, because circulating air from lower latitudes would completely replace the Ozone that broke down in the Arctic.
Can anyone tell me what the ozone levels were in the Antarctic in 1950? 1900? 1800? 1700? If no,t how can we tell if the ozone hole has changed or been affected by man or is it a natural phenomenon? Could it be that there are natural reasons that the ozone hole is behaving differently in the Arctic as compared to the Antarctic?
This seems a fairly straghtforward system, so it’s surprising that there would be any surprises
possible. But it seems as though the lack of both before and after mesurements of ozone layers
limits what can be said as to the effectiveness of the CFC ban, since other factors can and do affect the ozone holes.
One thing that I always found ‘irritating’ about the south pole ozone hole: How come those CFCs all migrated south, mostly crossing the equator, and did not stay at/near the north pole?
george e. conant says:
April 15, 2014 at 3:22 pm
CFC’s way to heavy to get above troposphere
Buoyancy does not apply to gases or liquids dissolved in gases. If it did, you would never see clouds above the ground since liquid water is much denser than air.
Point of the Entire Above Article:
One line: “‘A success story of science and policy.’”
It’s all about CONTROL (partly per se and MOSTLY for Enviroprofiteering).
They are SOOOO desperate it’s really sad.
A SUCCESS STORY! — SO LISTEN TO US!!!
Pathetic.
********************************
“… because international efforts to limit ozone-depleting chemicals have been successful.”
Unfounded, baseless, speculation, iow,
JUNK science.
First, a question. When did they obtain their data? This is significant because extreme cold conditions like we experienced this winter (Jan-Mar) can increase the depletion of ozone – that is why the Antarctic ‘hole’ has always been larger than the Arctic ‘hole’, because it experiences considerably more extreme cold temperatures than the Arctic experiences during their corresponding winters.
Second: Ozone has a very short lifetime (about 48 hours max) and is created in the ‘ozone layer’ by the photochemical reaction of UV radiation on Oxygen (O2). During a polar winter there is very little UV radiation so no ozone is being created to replace that which is naturally breaking down – thus, depletion of ozone in polar regions occurs naturally during a polar winter.
Third: The ‘hole’ in the ‘ozone layer’ is a naturally occurring phenomenon at both poles and it will never completely disappear. All the banning of man-made ODS (Ozone Depleting Substances) can hope to accomplish is to slow down the rate of ozone depletion which, in turn, would decrease the maximum extent of the ‘hole’.
“””””…..george e. conant says:
April 15, 2014 at 3:22 pm
CFC’s way to heavy to get above troposphere, Ozone probably blasted during all those above ground nuke tests for 30 odd yrs. The international ban on above ground nuke testing more likely a healing factor …. nice when things work……”””””
Just when did the Kiwis and Aussies do all those nuke tests own south that blasted the Antarctic ozone.
Antarctic ozone hole due to no sunlight during Antarctic winter midnight so no EUV to break down O2 into O which then makes O3.
Ozone is the result of OXYGEN absorbing dangerous UV radiation , and protecting life on earth from it.
Life on earth evolved in an oxygen free atmosphere so there was tons of UV on earth when life evolved.
When the oxygen disappear, then we will have a UV problem to worry about; dang; we won’t be here to worry about UV, sans oxygen in the atmosphere.
Ozone is overblown , holes or no. It is the evidence that oxygen is protecting us from solar UV.
If the vast majority of the chemicals that are supposedly destroying ozone are found in the northern hemisphere- which makes sense, because I do believe that is where most of them are used- HOW do they get down to the Antarctic?
Mr Smith Says:Just when did the Kiwis and Aussies do all those nuke tests own south that blasted the Antarctic ozone.
——
Perhaps it was the extensive French above ground nuke testing in French Polynesia that did it, It is well documented that Cesium and Strontium nucleides were distributed world wide regardles.
I am suspicious of this entire Ozone controversy.
First it seems to occur at the Antarctic pole, the most separated and isolated region from where the Halogens originated and were used, in the Northern Hemisphere. Why??
Secondly, after the Ozone hole was found in the mid 70s-early 80s and the Montreal Protocol was initiated to cure it. Some researchers went back and looked at data from the 1957 International Geophysical Year studies of Antarctica. The data shows an Ozone hole present back then, before much HVAC had spread worldwide.
Thirdly, an Antarctic volcano was spewing great quantities of Ozone destroying compounds into the Antarctic atmosphere. But the Montreal Protocol had been adopted, and these research results were ignored,amidst the backslapping and bon homie. .
Fourthly, the makers of flouro-halogens were anxious to agree to the Montreal Protocol, since the banning and replacements would replace ex-patent, commodity prices, with new and much higher prices for proprietary replacements. It would also require lots of new HVAC equipment too, as the new halogens were not at efficient as the older original ones. So a welcome profit opportunity beckoned for the refrigerant makers and the refrigerator makers, and their service companies. In short, the entire industry seemed to profit, so opposition was nullified.
From the London Times yesterday (Tuesday)
“Ozone hole means Britons face a burning problem
The spring sunshine is surprisingly strong, and has been made more so by a recent ozone hole over Britain, allowing high levels of ultraviolet rays to penetrate the atmosphere and burning unprotected fair skin.”
Behind paywall http://www.thetimes.co.uk/tto/weather/article4063546.ece
Now you know where the ozone hole has gone.
Considering that there is a thousand fold increase in UV between the poles and the equator I’ve never seen what all the fuss was about. A thousand fold increase means that if you move 100 mile south you DOUBLE your UV exposure (on average). The worst that I recall the threat of ozone depletion at the poles was a 10% increase in local UV levels – the same as moving ten miles south…Now this is just from memory, I looked into this over a decade ago and this is what I recall from my research. Could be totally wrong of course!
I know that almost everyone here has been exposed to my magnetic susceptibility explanation of the ozone holes: O2 quite magnetic (strongly paramagnetic) – more so when very cold; all other atmospheric gases diamagnetic i.e. pushed away by a magnet. I won’t go into it all again in detail, but expect there to be a CO2 hole, N2 hole, noble gases hole and methane hole coincident with the ozone hole. Expect an elevated concentration in the temperate and equatorial regions (latter probably disrupted and mixed with weather). If these differential concentrations of the other gases is correct, then the case for solely a chemical reaction reason for the ozone hole is very tenuous. Since no one is taking me up on the invitation to examine this, I’m planning to collaborate with a physicist specializing in magnetics on a paper of this subject.
Oh and look at the NASA image in the article of the “roll-necked” sweater band of concentrated ozone away from the hole.