Global ozone layer depletion leveling off – rising slightly

From the European Space Agency. By merging more than a decade of atmospheric data from European satellites, scientists have compiled a homogeneous long-term ozone record that allows them to monitor total ozone trends on a global scale – and the findings look promising.

Monthly mean total ozone

Monthly mean total ozone averaged over 60°N to 60°S from the merged GOME, SCIAMACHY and GOME-2 datasets (solid lines). The original datasets (dashed lines) before the adjustment are plotted for comparison. Credits: Diego Loyola, DLR

Scientists merged monthly total ozone data derived from the vertically downward-looking measurements of the GOME instrument on ESA’s ERS-2 satellite, SCIAMACHY on ESA’s Envisat and GOME-2 on the European Meteorological Satellite Organization’s MetOp-A.

“We found a global slightly positive trend of ozone increase of almost 1% per decade in the total ozone from the last 14 years: a result that was confirmed by comparisons with ground-based measurements,” said Diego G. Loyola R. who worked on the project with colleagues from the German Aerospace Center (DLR).

Ozone is a protective layer found about 25 km above us mostly in the stratospheric layer of the atmosphere that acts as a sunlight filter shielding life on Earth from harmful ultraviolet rays. The thinning of this layer increases the risk of skin cancer, cataracts and harm to marine life.

The ozone layer is not distributed evenly, with more changes occurring in the upper stratosphere. By collecting data while looking sideways (limb viewing) rather than vertically downwards, instruments are able to provide highly accurate measurements of the stratosphere.

Merged total ozone from GOME, SCIAMACHY and GOME-2 from June 1995 until May 2009.  Credits: Diego Loyola, DLR

Merged total ozone from GOME, SCIAMACHY and GOME-2 from June 1995 until May 2009. Credits: Diego Loyola, DLR

A team of scientists around Ashley Jones and Jo Urban from Sweden’s Chalmers University of Technology combined the limb measurements of US instruments SBUV, SAGE I+II and HALOE with data from OSIRIS, SMR and SCIAMACHY on the European satellites Odin and Envisat to analyse the long-term evolution of stratospheric ozone from 1979 to the present. These data show a decrease in ozone from 1979 until 1997, and a small increase since then.

“Our analysis shows that upper stratospheric ozone declines at northern and southern mid-latitudes at roughly 7% per decade during 1979–97, consistent with earlier studies based on data from satellites and ground networks. A clear statistically significant change of trend can be seen around 1997. The small increase (of 0.8–1.4% per decade) observed thereafter, from 1997 to 2008, is however not yet statistically different from a zero trend. We hope to see a significant recovery of (upper stratospheric) ozone in the next years using longer, extended satellite time-series,” Urban said.

Upper stratospheric ozone anomalies

Upper stratospheric (35-45km) ozone anomalies for six instruments at northern mid-latitudes (30N–60N). Shown are SAGE I+II (blue, A), SBUV/2 (orange, B), UARS/HALOE (red, C), Odin/SMR (magenta, D), Odin/OSIRIS (black, E), and Envisat/SCIAMACHY (cian, F). Also shown under-laid is the all instrument average (green). Thin black lines indicate the fitted trends before and after 1997.

The thinning of the ozone layer is caused by chemicals such as human-produced bromine and chlorine gases that have long lifetimes in the atmosphere. The Montreal Protocol (1987) was introduced to regulate and phase out the production of these substances. Its effect can clearly be seen in the satellite observations of ozone and these chemicals.

Using SCIAMACHY data in limb-viewing observation mode from 2002 to 2008, François Hendrick from the Belgian Institute for Space Aeronomy (BIRA/IASB) and his colleagues from the University of Bremen performed a trend analysis of bromine monoxide (BrO) in the stratosphere. BrO is a highly efficient catalyst in ozone destruction. The results show a negative trend in BrO abundance in the stratosphere during this period, marking the first time a decline in stratospheric bromine has been reported from a spaceborne observation.

Monthly averaged BrO column abundances

Time series of monthly averaged BrO column abundances measured over Harestua (60°N, 11°E) by SCIAMACHY limb (right) and ground-based UV-visible (left) instruments. Thick lines indicate trend analysis results. A decline of -0.6+/-0.3% per year is estimated from SCIAMACHY limb observations over the 2002-2008 period, which is in good agreement with ground-based UV-visible measurements (-0.7+/-0.3%/year). Credits: F. Hendrick (BIRA/IASB) and A. Rozanov (IUP/IFE-Bremen), 2009

“The good agreement with ground-based observations at high and mid-latitudes show that SCIAMACHY limb data can be used for stratospheric BrO trend monitoring. These findings provide strong evidences that the Montreal Protocol restrictions on brominated substances have now reached the stratosphere,” Hendrick said.

Having access to these atmospheric satellite data over long periods is important for scientists to identify and analyse long-term trends and changes. In addition to monitoring ozone trends, scientists will continue to monitor ozone-depleting substances that were phased out under the Montreal Protocol but continue to linger in the atmosphere.

All of these results were presented at ESA’s five-day ‘Atmospheric Science Conference’ held in Barcelona, Spain, 7–11 September. The objective of the conference was to provide scientists and researchers with the opportunity to present up-to-date results from their atmospheric research and application projects using space-based atmospheric sensors.

The conference, with some 200 participants, included presentations that detail the current use of satellite instruments for remote sensing of trace gases in the stratosphere and troposphere, clouds and aerosols, pollution and greenhouse gas monitoring.

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60 thoughts on “Global ozone layer depletion leveling off – rising slightly

  1. I saw once the concentration of chlorine gases over Antarctica during the last years (similar to the BrO series above). Was this on WUWT? Or somewhere else?
    Has anyone a link?

  2. Johnny Honda,
    Are you be thinking of this article?
    ScienceDaily (July 27, 2007) — Large quantities of ozone-depleting chemicals have been discovered in the Antarctic atmosphere … The source of the halogens is natural — sea-salt in the case of bromine, and in the case of iodine, almost certainly bright orange algae that coat the underside of the sea ice around the continent. These halogens cause a substantial depletion in ozone above the ice surface … Dr Alfonso Saiz-Lopez, have confirmed that iodine oxides are widespread throughout coastal Antarctica.
    John Plane, professor of atmospheric chemistry at the University of Leeds, says: “Halogens in the lowest part of the atmosphere have important impacts on ozone depletion …The research was published by Science.”
    http://www.sciencedaily.com/releases/2007/07/070726104756.htm

  3. The thinning of the ozone layer is caused by chemicals such as human-produced bromine and chlorine gases that have long lifetimes in the atmosphere. The Montreal Protocol (1987) was introduced to regulate and phase out the production of these substances. Its effect can clearly be seen in the satellite observations of ozone and these chemicals.
    This is part of the “look what international regulation has done for the planet”
    approach that will be quoted for Copenhagen.
    For some different facts on Ozone check here:
    http://junkscience.com/Ozone/ozone_seasonal.html

  4. Why is there a much larger hole over the south pole rather than the north pole?
    Is it because 90% of the world’s industry is in the southern hemishere, or is it because the earth is slightly pear shaped and ozone producing photons find it harder to hit oxygen at the bottom of the pear?

  5. Assuming the corner has been turned (not yet certain), can we reliably distinguish between the effects of the Montreal Protocol and the reduced activity of the sun since cycle 23 failed to match the intensity of the previous solar cycles ?

  6. I try to summarize, what appears to be the ESA summary of a 200 participants’ conference:
    In the first graph, which spans the years 1996 to 2008, there appears to be a slight increase in ozone concentration up to 2003, then a drop. The drop lies between the two violet ellipses. I understand, various satellite data had to be merged. I also understand, this merging is considered successful.
    The second graph (after the movie) shows a combination of satellite and earth bound (?) data. They span the years 1979 to 2008. They first show a decrease until 1997, then a slight increase, which, maybe, is not yet statistically significant.
    On a second look, the first graph takes an average between 60 north and 60 south (no altitudes are given, possibly in the Dobson spirit an average over all altitudes?). The second graph takes the averages between 30 north and 60 north, and between 35 and 45 km altitude.
    So, what do we learn? Are we still confused, but now on a very much higher level?
    In any case, graph 2 very probably shows a signature of the Pinatubo eruption, in the data around 1993, and maybe, that little spike at the beginning of 1983, could that be El Chicon?

  7. The most famous example of previous ozone depletion is the ‘hole’ over the antarctic. I once posed this question to the Max Planck Institute and Cambridge University
    “How do we know that there hasn’t ALWAYS been an ‘ozone hole’ over the Antarctic-and that it varies in size?
    I had lots of very learned papers cited (I don’t think they had ever considered it before) and the upshot was that they didn’t know the situation before they developed the ability to measure the hole during the late 50’s. That the depletion was partially caused by the exceptionally cold antarctic of recent yeats was also an interesting factor.
    Claiming the oxone hole is repairing itself (which no doubt is a good thing) is therefore a little like clainmg the arctic ice cap is at its lowest level ever, then admitting that ‘ever’ refers to records that only go back an eyeblink in time.
    http://www.pnas.org/content/104/2/445.full.pdf
    This compares Arctic and Antarctic depletion
    Interestingly there is a reference to the cosmic ray theory/ozone hole theory as far back as 2001
    http://focus.aps.org/story/v8/st8
    Checking further back I then find that the scientist concerned, Qing-Bin Lu, has written a new paper stating the ozone hole is not depleting-last year was I believe the second highest on record. Whether ozone worldwide is increasing and how much it is linked to temperatures globally is another matter.
    tonyb

  8. Why do I find myself wanting to groan about yet another grafted together homogenized data series?…
    And I’m now feeling skeptical about the “chemicals cause ozone depletion” thesis too. The seasonal variations are so large that seems to dominate. Solar variation in UV production (that makes O3) also varies rather much. So do we REALLY know that it isn’t just UV variations and variation in the solar wind / energetic particle impact? If not, then just exactly WHY is the N. Pole so high in ozone? Looks like a Birkeland Current signature to me.
    If we get a flip of what pole the solar current lands upon, I’d bet we also get a flip of which pole has an ozone hole. Wonder if there is any way to dig that out of ocean sediments along with the magnetic polarity of the planet…

  9. Johnny Honda,
    You may also be interested in this article:
    “ScienceDaily (June 26, 2008) — Large amounts of ozone — around 50% more than predicted by the world’s state-of-the-art climate models — are being destroyed in the lower atmosphere over the tropical Atlantic Ocean…
    So, what’s causing this loss? Instruments developed at the University of Leeds, and stationed at the Observatory, detected the presence of the chemicals bromine and iodine oxide over the ocean for this region. These chemicals, produced by sea spray and emissions from phytoplankton (microscopic plants in the ocean), attack the ozone, breaking it down…
    Professor John Plane, University of Leeds said: “This study provides a sharp reminder that to understand how the atmosphere really works, measurement and experiment are irreplaceable. The production of iodine and bromine mid-ocean implies that destruction of ozone over the oceans could be global”. ”
    http://www.sciencedaily.com/releases/2008/06/080625140656.htm

  10. Isn’t the life expectancy of an ozone molecule about 30 minutes? Isn’t ozone formed by sunlight striking oxygen? Doesn’t oxygen actually absorb 97% of UV’s and ozone about 3%. Doesn’t the angle of incidence of sunlight to atmosphere have something to do with the concentration of ozone at the equator? Doesn’t the extreme cold at Antarctica stop the formation of ozone? If these things are true, then one’s altitude and latitude have a great deal more to do with UV exposure than atmospheric chemicals. And, incidentally, doesn’t the ozone hole actually cover the entire dark side of the earth? Doesn’t ozone have seasonal variations? (See Graph above.)
    For the record, I oppose the introduction of chemicals into the atmosphere, lithosphere, and the hydrosphere. But as a former science teacher I feel some of this ozone hysteria is slightly over-done.
    I favor getting the facts and thoughtfully considering them before running naked through the streets yelling something.

  11. OT – New one from the BBC’s Richard Black, entitled ‘Millions at risk’ as deltas sink :
    http://news.bbc.co.uk/1/hi/sci/tech/8266500.stm
    I almost fainted when I read it, esp. coming from Mr B, it has phrases including:
    “This study shows there are a host of human-induced factors that already cause deltas to sink much more rapidly than could be explained by sea level alone.”
    Crikey!
    This is significantly more than the global rate of sea level rise as a consequence of climate change (1.8-3.0mm per year).
    Blimey!
    Is he finally producing a piece of work that _doesn’t_ lay the blame of any change at the feet of CO2? Is he also acknowledging that the top end figure of sea-level rise is 3mm a year, i.e. 30cm (or about a foot) in a century (hardly much to get worked up about)?
    Cheers
    Mark

  12. The Montreal Treaty is one of the backdoor solutions that Obama has figured out to limit CO2 Emissions, in case the Waxman Bill or EPA don’t deliver.
    An enormous amount of spin and hog wash Alarmism has been published about the Ozone layer, eventually leading to the Montreal Treaty.
    After the agreement the world was forced to use a patented alternative.
    And more spin is underway as the Green Movement will use any opportunity at any price to put the green shackles on humanity.
    The last words on the Ozone Layer have not been siad.
    http://www.nature.com/nature/journal/v449/n7161/full/449382a.html
    Other Examples:
    http://www.earth-stream.com/Earth/Continents/Australia-and-NZ/Livestock-gas-now-biggest-risk-to-ozone-layer_18_197_721_203081.html
    http://www.dailymail.co.uk/sciencetech/article-1172532/Sea-ice-Antarctic-increasing-result-ozone-hole-reveals-new-research.html

  13. The following paper, which I managed to download awhile back, seemed to address the man-made ozone depletion nonsense very comprehensively. It seems to be available in bookform now, and it may be worth a search to see if the free pdf download is still out there. (Sorry, I’ve lost my original link)
    The Holes in the Ozone Scare: Scientific Evidence that the Sky Isn’t Falling
    by Rogelio A. Maduro and Ralf Schauerhammer
    Mike A

  14. I often wondered, why does a hole in the ozone layer at the poles bother us at all? It’s not as if any UV will be coming through them. In Oz, people get skin cancer, and blame it on the ‘hole in the ozone’ instead of staying in the tropical sun all day as a kid, but from there sunlight will never reach anywhere near us in Oz.
    I also, as others have stated above, am getting curious as to whether we had anything to do with the ozone layer. I think now (seeing the constant BS about life-giving CO2) that scientists may have been mistaken and the records were really not long enough. Having said that, getting rid of CFCs didn’t bankrupt us like getting rid of CO2 will (just writing it makes me feel ill).

  15. CFC Albuterol inhalers were $5.00 (generic); now illegal.
    New patented HFC inhalers $65.00 (no generics).
    There’s a hole alright and her name is Carol Browner.

  16. “JER0ME (05:06:29) :
    I often wondered, why does a hole in the ozone layer at the poles bother us at all?”
    It was worce than that actually. CFC’s released in the NH were supposed to, magically, acculumate over the south pole. A miracle!
    “It’s not as if any UV will be coming through them. In Oz, people get skin cancer, and blame it on the ‘hole in the ozone’ instead of staying in the tropical sun all day as a kid, but from there sunlight will never reach anywhere near us in Oz.”
    You may wan to check up on the sunlight thing. I see it every day, but I can feel the UV.
    “I also, as others have stated above, am getting curious as to whether we had anything to do with the ozone layer. I think now (seeing the constant BS about life-giving CO2) that scientists may have been mistaken and the records were really not long enough. Having said that, getting rid of CFCs didn’t bankrupt us like getting rid of CO2 will (just writing it makes me feel ill).”
    But is the ozone hole decrease a direct result of the banning of CFC’s? Who knows, but I am sure someone will make claim to it.

  17. Production of ‘ozone depleting chemicals’ did not end in 1989. In fact, it still continues today in some counties. The leaking of such chemicals into the atmosphere did not stop in 1989. We were told that such chemicals stay in the atmosphere for many decades. Therefore, the amount of man-made ‘ozone depleting chemicals’ currently in the atmosphere should be higher now than ever before, yet the ozone layer is not diminishing, but recovering.
    How is this possible?
    Simple…humans have little to do with the ozone layer. Our chemicals have almost no effect compared to natural variations. Time will show this to be true, but long after the damage is done through the fear mongering of the global population and the pontificating of the Montreal Protocol.
    By the way, the increase in UV radiation from the ‘depletion of the ozone layer’ in the 80s and 90s, was equivalent to moving about 60 miles closer to the equator. If this was a problem, all the snowbirds who moved from New England to Florida during that time (about 1,200 miles closer to the equator) should have been instantly vaporized! Instead, the spent their time in the Florida sun working on their golf game.
    The Montreal Protocol was a wonderful example of government implementing an expensive solution to no problem whatsoever.

  18. The Montreal Protocol was about Du Pont’s patent running out…we now know the solar variation coincides with UV production. The UV hole is as big as it ever was, another wasted effort akin to the AGW thesis.

  19. this is something i’m ignorant of altogether. However, we know in ozone, oxygen in three is involved and that chlorine is th e main catalyst. From what I understand (i’m no expert in this field) most chlorine is natural and not anthropogenic. CFC’s, containing halogen, nitrous oxide, etc we know from laboratory experiments deplete ozone. However, they all occur naturally and they are heavier than air, so left in a room, cfc’s pool on th efloor.
    Athough wind currents and eddies are able to transport them upwards, the question is: Are they able to transport them to the stratosphere, and if so in sufficient quantities to cause depletion? Are there any empirical studies of anthropogenic ozone depletion?
    Finally, are, or have anthropogenic sources been present in the ozone environment enough to justify what at the moment is ashort term trend?

  20. The sun creates ozone the sun destroys ozone. Look at the balance of UV A vs B for details.
    Does anybody know how the two track with a roaring sun and a quite sun? Links?

  21. The “CFC’s are destroying the ozone” was all bunk. When the actual measurements of the rates at which the CFC-derivatives were finally down last year, the rate was 10 times lower than the models had all assumed. We destroyed whole industries and made anything with a compressor more expensive and less efficient, all in the name of saving the planet.
    Sound familiar?

  22. We used to use Freon as a component cooler, contact cleaner, fire extinguisher, aerosol propellant, refrigerant, and many other things.. The 1987 service manuals for my car tell you to detect AC leaks by filling the system and looking for bubbles. The last cans I got for my car’s AC were $3, the last time I know of someone filling their Freon AC system (from recovered Freon, it’s unlawful to manufacture it) they spent over $300.
    Instead of going to R134a, I went to Propane. It’s a more effective refrigerant than R134a anyway, but for obvious reasons we’re a little careful about using it in a car. After a crash, nobody wants to be surrounded by a cloud of explosive gas.
    The Ozone scare was just the training exercise for the AGW scare. They learned the buttons to push, and discovered that people really will believe any steaming pile of crap as long as it’s prefixed by “Scientists Say…”

  23. We were told that these CFC’s were so long-lasting that they’d be destroying ozone at an exponential rate for eons into the future. This of course was an indisputable fact…. Then again it’s only 10 years so it’s surely just noise in an ever-rising trend.
    I actually first read about aerosols and ozone as a kid reading Marvel comics. They had a storyline about the skin cancer getting so bad in the future that the people were forced to become cyborgs to replace missing body parts.
    Wait a minute; a rise from 1979 to 1997 then a plateau. Is that a spurious correlation I see before me?

  24. “After a crash, nobody wants to be surrounded by a cloud of explosive gas.”
    You don’t think theres a market for hydrogen cars then?

  25. I believe the ‘ten times lower’ reference relates to this topic. Actual kinetic data (as opposed to estimates used in the 1980s) showed that a key reaction rate was almost an order of magnitude slower than had been estimated. This led to the quote – “This must have far-reaching consequences,” Rex says. “If the measurements are correct we can basically no longer say we understand how ozone holes come into being.” excerpts from the article follow:
    ———————————
    Chemists poke holes in ozone theory
    News@Nature, 26 September 2007
    http://www.nature.com/news/2007/070924/full/449382a.html
    As the world marks 20 years since the introduction of the Montreal Protocol to protect the ozone layer, Nature has learned of experimental data that threaten to shatter established theories of ozone chemistry. If the data are right, scientists will have to rethink their understanding of how ozone holes are formed and how that relates to climate change.
    Markus Rex, an atmosphere scientist at the Alfred Wegener Institute of Polar and Marine Research in Potsdam, Germany, did a double-take when he saw new data for the break-down rate of a crucial molecule, dichlorine peroxide (Cl2O2). The rate of photolysis (light-activated splitting) of this molecule reported by chemists at NASA’s Jet Propulsion Laboratory in Pasadena, California1, was extremely low in the wavelengths available in the stratosphere – almost an order of magnitude lower than the currently accepted rate. “This must have far-reaching consequences,” Rex says. “If the measurements are correct we can basically no longer say we understand how ozone holes come into being.” What effect the results have on projections of the speed or extent of ozone depletion remains unclear.
    The rapid photolysis of Cl2O2 is a key reaction in the chemical model of ozone destruction developed 20 years ago2 (see graphic). If the rate is substantially lower than previously thought, then it would not be possible to create enough aggressive chlorine radicals to explain the observed ozone losses at high latitudes, says Rex. The extent of the discrepancy became apparent only when he incorporated the new photolysis rate into a chemical model of ozone depletion. The result was a shock: at least 60% of ozone destruction at the poles seems to be due to an unknown mechanism, Rex told a meeting of stratosphere researchers in Bremen, Germany, last week.

  26. E.M.Smith (01:17:54) :
    ‘So do we REALLY know that it isn’t just UV variations and variation in the solar wind / energetic particle impact? If not, then just exactly WHY is the N. Pole so high in ozone? Looks like a Birkeland Current signature to me.
    If we get a flip of what pole the solar current lands upon, I’d bet we also get a flip of which pole has an ozone hole. Wonder if there is any way to dig that out of ocean sediments along with the magnetic polarity of the planet…’
    Now there’s a possible grant-worthy research project surely. Is there a suitable proxy? Would subaerial lavas be better than seabed lavas? Can anyone develop this?

  27. The excerpts I quoted on ozone kinetics are from this link for those who may want to read more.
    http://groups.google.com/group/alt.politics/browse_thread/thread/d68c75cd9a454d73/37d6d42ca985cedd?lnk=raot
    The link in my earlier post goes to a Nature premium content abstract.
    ———————-
    This related opinion posting also covers the ozone kinetics topic
    Ozone chemistry confounds everyone
    New research throws our understanding of the chemistry driving ozone depletion into doubt.
    By Chris Lee | Last updated October 1, 2007 8:59 AM CT
    http://arstechnica.com/science/news/2007/10/ozone-chemistry-confounds-everyone.ars

  28. JamesG, people drive Priuses (Prii?), so there’s a market for pretty much any useless vehicle technology if it’s sold as “saving the planet”…
    (Yes, that was intended as humor)

  29. Well when I look at that ozone graphs, I see a very prominent annual cyclic variation in ozone; something which has been well known by proxy for eons; due to studies of the effective color temperature of ground based solar radiation measurements. These annual variations as well as other more random changes in the color temperature are attributed to changes in the UV and short wavelength (below the peak) solar spectrum that makes iut through the atmosphere.
    These studies point to the existence of ozone holes long before there were freons to blame for what seems to be a perfectly natural variability.
    Ozone is also an important GHG specially in the tropics, so it is not something we want to be messing around with in the belief that we can engineer a better climate.

  30. The move away from freon made cooling more expensive and less efficient. That means it took more energy to produce the same amount of cooling. More energy means more CO2 emitted from the burning of fossil fuels. So, yes, the elimination of freon led to more man-made global warming! Obviously, the real threat to the planet is modern environmentalism:-)

  31. E.M.Smith (01:17:54) :
    “…And I’m now feeling skeptical about the “chemicals cause ozone depletion” thesis too. The seasonal variations are so large that seems to dominate. Solar variation in UV production (that makes O3) also varies rather much. So do we REALLY know that it isn’t just UV variations and variation in the solar wind / energetic particle impact? If not, then just exactly WHY is the N. Pole so high in ozone? Looks like a Birkeland Current signature to me…
    Reply: I think you are onto something here. This could be part of the mechanism by which the solar cycle effect earth’s climate. If the current quiet sun continues, we should be able to observe if this hypothesis could be true.

  32. For the record, the story line above says that the ozone layer forms about 25 km high above the earth’s surface. That puts it at about 40,000 ft altitude.
    so why would it matter temperature wise whether you are over Antarctica of over the equator; at 40,000 feet it doesn’t matter much.
    The story also says that chlorine and Bromine appear in the atmosphere from salt spray.
    I suspect that the ocean is the largest source of bromine worldwide; haven’t ever heard of anybody minig bromine on land.
    At least in California, farmers aren’t aloud to use ethyl bromide any more to stop their crops from rotting.
    So it seems to me that chemical destruction of ozone is probably quite natural and beyond our control.
    Ozone is far less stable than oxygen, and in order to get ozone you first have to decompose O2 molecules, and that takes out the short wave UV.
    Life on earth evidently evolved before there was either oxygen or ozone to protect us from UV; so I doubt that life will cease to exist, with ozone holes that are just part of the natural environment and beyond our control.
    In any case ozone is a GHG so we don’t want too much of it anyway.

  33. The Montreal Protocol substituted ozone depleting gases with known powerful synthetic greenhouse gases.
    Synthetic Greenhouse Gases (SGGs) were largely introduced as replacements for some ozone-depleting substances. Three of the six Kyoto Protocol gases – hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6) – are SGGs. While these gases do not present a direct risk to the ozone layer, they often have very high Global Warming Potentials (GWPs) and will contribute significantly to the enhanced greenhouse effect if emitted to the atmosphere.
    http://www.environment.gov.au/atmosphere/ozone/index.html
    The Montreal Protocol is causing global warming.
    Even I was shocked to discover this.

  34. Dave in Delaware (10:07:20) :
    Those questions are now claimed to have “been resolved.”
    http://www.nature.com/news/2009/070509/full/news.2009.456.html
    Without calling into question the chemistry of ozone depletion, which I generally think is sound, I still continue to be puzzled over actual atmospheric ozone levels. In an earlier discussion on ozone depletion on WUWT, phil.dot linked to this useful site and referred to Figures 8&9
    http://omsriram.com/GlobalWarming.htm
    Those cfc levels certainly are consistent with ozone recovery starting in “about 1997”. But my poor ole eyes look at the six instrument anomaly figure in Anthony’s post and I swear the recovery seems to be starting in the early 90s. As someone alluded to above, Pinatubo did distort ozone measurements then (which led to a lot of hyped-up “OMB, it’s worse than we thought” reporting back then), but it still looks curious to me.
    Here’s another graph that show the Pinatubo effect more clearly.
    http://www.iac.ethz.ch/en/research/chemie/tpeter/totozon.html
    Again, recovery seems to be earlier than the late 90s. but then, how do you back out Pinatubo?

  35. DocWat (01:41:02) :
    Isn’t the life expectancy of an ozone molecule about 30 minutes?

    No, more properly the lifetime of odd-Oxygen is months.
    Isn’t ozone formed by sunlight striking oxygen?
    No, but odd-Oxygen is.
    Doesn’t oxygen actually absorb 97% of UV’s and ozone about 3%.
    No.
    Doesn’t the angle of incidence of sunlight to atmosphere have something to do with the concentration of ozone at the equator? Doesn’t the extreme cold at Antarctica stop the formation of ozone?
    No.
    If these things are true, then one’s altitude and latitude have a great deal more to do with UV exposure than atmospheric chemicals. And, incidentally, doesn’t the ozone hole actually cover the entire dark side of the earth?
    No.
    Doesn’t ozone have seasonal variations? (See Graph above.)
    Got one right at last!
    For the record, I oppose the introduction of chemicals into the atmosphere, lithosphere, and the hydrosphere. But as a former science teacher I feel some of this ozone hysteria is slightly over-done.
    I favor getting the facts and thoughtfully considering them before running naked through the streets yelling something.

    Perhaps you should start getting the facts then.

  36. When the boogeyman was Nuclear Winter, we were assured that the Southern Hemisphere would be a better place to be because the majority of the bombs would be exploded in the N. Hemi. and the opposing windbelts at the equator would delay or stop the passage of the fallout and smoke. Then we were told that N. Hemi. CFCs went straight to the S. Pole to do in the precious ozone. Nat. Geographic, in an article on Antarctica, stated that Mount Erebus was discharging tons of Hydrogen Chloride right in the middle of the South Polar Gyre. I think that the Montreal Protocol was another swindle.

  37. mr.artday (21:02:24)
    http://www.mfe.govt.nz/publications/ser/ser1997/html/images/figure5.18.gif
    http://www.mfe.govt.nz/publications/ser/ser1997/html/chapter5.8.html#figure5.18
    After the Antarctic Ozone Hole was discovered, some scientists took the view that it might be a natural event caused by volcanic chlorine emissions from Mount Erebus rather than manufactured chlorinated chemicals. Eventually, however, Mount Erebus was exonerated (Zredna-Gostynska et al., 1993). Most of the chlorine Mount Erebus throws up takes the form of hydrogen chloride (HCl), which (like other chlorine from natural sources) readily dissolves in the water vapour of the lower atmosphere well before it can reach the stratosphere.
    For Mount Erebus to affect the ozone layer, the volcano would have to inject a large proportion of its hydrogen chloride directly into the stratosphere, above a height of about 10 km. Mount Erebus has been active since it was first observed by James Ross in 1840, but appears never to have erupted with the force necessary to send chlorine directly into the stratosphere. The mountain itself is almost 4,000 m high (3,794 m), but the volcanic plume seldom rises above 5,000 m. The amount of gas Mount Erebus emits also bears no relation to the size of the ozone hole. In the summer of 1983, chlorine emissions from Mount Erebus were about 170 tonnes a day. In the following seven summers, when ozone depletion was even more severe, the chlorine emissions ranged from one-tenth to one-quarter of the 1983 figure (Zreda-Gostynska et al., 1993).

  38. From Junk Science (perhaps it’s all in the title)
    http://junkscience.com/Ozone/ozone_seasonal.html
    Is “the hole” of any real significance to people or the planet? Not so far as anyone can tell.
    Should we worry about it? Unless you’re a scientist earning a living from it, it’s probably not worth a second thought
    http://www.mfe.govt.nz/publications/ser/ser1997/html/chapter5.8.html#figure5.18
    UV-B related cancers are not confined to humans. Where pigs and goats, cattle and horses have inadequate access to shade they also fall victim to skin and eye cancers, and their exposure is less subject to seasonal fashions. It is not known whether their melanoma rates have increased in recent years. Plants are also affected by excessive UV-B light, and, because they rely on direct sunlight for energy, many species have developed protective mechanisms against high levels of UV-B. Despite this, experiments have shown that cotton, peas, beans, melons, and cabbage grow more slowly under intense UV-B, and pollen fails to germinate in some plants. Plant hormones and chlorophyll, the chemical mainly responsible for photosynthesis, can also be damaged. New Zealand scientists are currently studying ways of making crop plants more ultraviolet-resistant through selective breeding programmes and gene modification (Markham and Ryan, 1996
    Aquatic ecosystems are also vulnerable. UV-B can penetrate clear water to a depth of many metres, posing a threat to single-celled algae which are known from laboratory studies to be sensitive to UV-B. These organisms are at the very base of the aquatic food chain, and are also major consumers of carbon dioxide and emitters of anti-greenhouse sulphate aerosols. A serious reduction in algal biomass could therefore reduce fish populations and enhance the build-up of greenhouse gases in the atmosphere.
    A study of Antarctic algae which were shielded from UV-B radiation by ice found no change in species composition over two decades of ozone depletion (McMinn et al., 1996). However, a survey of algal blooms in open water found that biomass (total weight) fell by 6-10 percent in the waters where UV-B was most intense, beneath the springtime ‘ozone hole’ (Smith et al., 1992). This represents about 7 million tonnes of lost photosynthesis per year, or a 2 percent depletion of the Southern Ocean’s phytoplankton. The researchers noted that this reduction, though significant, was small compared to the seasonal advance and retreat of the ice pack which causes biomass reductions as high as 50 percent.

  39. http://wapedia.mobi/en/File:Sources_of_stratospheric_chlorine.png
    http://wapedia.mobi/en/Ozone_depletion?t=7.
    Another objection occasionally voiced is that It is generally agreed that natural sources of tropospheric chlorine (volcanoes, ocean spray, etc.) are four to five orders of magnitude larger than man-made sources. While strictly true, tropospheric chlorine is irrelevant; it is stratospheric chlorine that affects ozone depletion. Chlorine from ocean spray is soluble and thus is washed out by rainfall before it reaches the stratosphere. CFCs, in contrast, are insoluble and long-lived, which allows them to reach the stratosphere. Even in the lower atmosphere there is more chlorine present in the form of CFCs and related haloalkanes than there is in HCl from salt spray, and in the stratosphere halocarbons dominate overwhelmingly. [51] Only one of these halocarbons, methyl chloride, has a predominantly natural source [52] , and it is responsible for about 20 percent of the chlorine in the stratosphere; the remaining 80% comes from manmade compounds.
    CFCs are well mixed in the troposphere and the stratosphere. The reason the ozone hole occurs above Antarctica is not because there are more CFCs there but because the low temperatures allow polar stratospheric clouds to form. [55] There have been anomalous discoveries of significant, serious, localized “holes” above other parts of the globe. [56

  40. As shown by the animation above there is a difference between the north pole and the south pole, the ozone hole.
    I agree with the proposition that it is not of anthropogenic origin but caused by the sun itself, through the reduction of ozone by protons (hydrogen nucleus), producing water as the result.

  41. The geo and solar magnetic fields may turn out to be far more influential than realised on climatic oscillations and inverse relationships ( viz conflicting temperature trends, ozone and probably a lot more). NASA seem to keep discovering startling new information emerging from their various mission probes, for instance that highlighted last December on this site-
    http://wattsupwiththat.com/2008/12/16/earths-magnetic-field-has-massive-breach-scientists-baffled/

  42. Everythingok (05:46:34) : there is a difference between the north pole and the south pole, the ozone hole … but caused by the sun itself, through the reduction of ozone by protons (hydrogen nucleus)
    I assume you must live in a desert to have buried you head so far in the sand!
    I think it is obviosly LGM (little green men) with a large vacuum cleaner sucking the ozone away to repair their planet – prove it is not!

  43. http://www.soest.hawaii.edu/GG/ASK/volcanic_chlorine.html
    Volcanic eruptions account for a large flux of chlorine from land to the atmosphere on a yearly basis. This is in addition to chlorine that enters the atmosphere from sea spray, industrial processes and biological gases. All of these inputs occur near or at the base of the atmosphere (the planet’s surface). Very little of the material emited from volcanoes makes it up into the higher reaches of our atmosphere (the stratosphere) where it could affect the ozone layer, however. Most of it is believed to be depositied lower down (in the troposphere), where it then rained out back to the surface of the earth. Only during fairly rare, large, explosive eruptions, such as occured a few years back at Mt. Pinatubo, do large amounts of volcanic gases reach the stratosphere.
    So why do chlorofluorocarbons reach the upper atmosphere when they too are only input at the base of the atmosphere? Because the latter are much more stable in the lower atmosphere, so they become well distributed and make their way to the stratosphere via atmospheric circulation. On the other hand, chlorine from volcanoes is usually emitted as hydrochloric acid (HCl), chlorine gas (Cl2) or volatile compounds such as lead chloride (PbCl2). Each of these is far more water soluble and/or reactive in the lower atmosphere (as compared to chlorofluorocarbons) so these volcanic gases tend not to be as uniformly distributed in the atmosphere following injection by a volcano.
    …we have a very poor handle on what, if any, natural causes there may be for its density to change over short time intervals. Thus, although the case for the role of chlorofluorocarbons is convincing, it is difficult to say if even it is the culprit (or at least if it did or didn’t have help from other gases). My own opinion is that a responsible society should always act to curtail the addition of substances deemed potentially hazardous even if there is compelling but not necessarily absolute evidence (which is the case for chlorofluorocarbons), since the balance of nature is far too complex a thing to risk toying with.
    Dr. Ken Rubin, Asistant Professor
    Department of Geology and Geophysics
    University of Hawaii, Honolulu, HI 96822

  44. Common myths about ozone depletion:
    Myth: CFCs cannot reach the stratosphere because they are heavier than air.
    Fact: Air in the lower atmosphere (which extends far above the stratosphere) moves in masses, not as individual molecules. A number of studies have found CFCs and the products of their breakdown in the stratosphere (Rowland, EPA).
    Myth: Volcanoes and other natural sources contribute much more chlorine than CFCs to the ozone layer.
    Fact: Chlorine compounds from natural sources are soluble, and so are washed out of the atmosphere. CFCs, by contrast, are not soluble and so are able to reach the stratosphere. A number of studies have shown that the majority of chlorine in the stratosphere comes from man-made chemicals (Rowland, Taubes, Russell et al, EPA).
    Myth: The Antarctic ozone “hole” was there all along, it was discovered in the 1970’s because that’s when satellite measurements started.
    Fact: The hole was discovered using a ground based instrument that had been in use since 1956. There was no hole until about 1976. That means about 20 years with no hole. Since the 70s the hole has continued to increase in size and intensity (Farman, et al, Jones & Shanklin).
    Myth: The “hole” was present when the first measurements were made in 1956.
    Fact: The first ozone measurements made in the Antarctic were lower than similar measurements made in the Arctic. However, this is the natural condition, not the decrease that is referred to as the ozone “hole”. As noted above, there was no “hole” during the first 20 or so years of measurement. (Parson, Christie).
    Myth: Some French researchers found an ozone hole in 1958.
    Fact: Paul A. Newman (Newman) looked at all the facts and found that “There is no credible evidence for an ozone hole in 1958.”
    Myth: Spray cans deplete the ozone layer.
    Fact: Spray cans (in the United States) have not used CFCs as propellants for about 20 years.
    Myth: Of course there is an ozone hole in the winter, there is no sunlight to make new ozone.
    Fact: The ozone hole occurs in the spring, after the sunlight returns. There is little destruction or creation of ozone during the winter (Parson)
    Myth: DuPont supported the ban on freon because the patent was about to run out.
    Fact: The patent for making freon was issued in 1928, it ran out in the 1940s, long before any concern about ozone depletion. (The History of Freon)
    Jim Norton- http://info-pollution.com/common.htm

  45. bill (09:07:25) :
    Myth: bill is your real name.
    Fact: It is not.
    REPLY: And your name is not “Greendoubts” Adolfo Giurfa, and even though you are on the skeptic side, I’ve told you many times you aren’t welcome here anymore, due to some of the angry and inflammatory things you say. Yet you keep changing screen names and coming back as a different persona. I’ve allowed this comment to show your hypocrisy. There won’t be any further from you. – Anthony

  46. Greendoubts (09:32:15)
    You are of course correct Bill is not my name.
    My real name would probably mean nothing or everything to you. Posting anonimously means What I Post stand or falls on its veracity and content not on my status in the scientific community.
    I stand by all I post and often will post AGW and non-AGW information (e.g. bill (08:58:04) : I could easily have missed out the final paragraph. But despite being a greenie, a probable warmist, a believer in “windmills” I really only want the truth.!!!!
    Seing others post unsubstantiated “truths” makes me mad!

  47. bill (12:31:32) : “Seing others post unsubstantiated “truths” makes me mad!”
    You have certainly managed to sow confusion in my mind on the “ozone hole”, anyway, bill, Greendoubts, Adolfo Giurfa… Sources you have pointed to conflict with others I have worked through and I am left puzzling without sufficient science to clinically analyse what I am reading to reach a conclusion ─ so I will keep reading here and elsewhere in hope of enlightenment and belief; either way.

  48. Bill said
    “Fact: The hole was discovered using a ground based instrument that had been in use since 1956. There was no hole until about 1976. That means about 20 years with no hole. Since the 70s the hole has continued to increase in size and intensity (Farman, et al, Jones & Shanklin).”
    Bill you are making an assumption .In my earlier post I said:
    “TonyB (01:05:36) :
    The most famous example of previous ozone depletion is the ‘hole’ over the antarctic. I once posed this question to the Max Planck Institute and Cambridge University
    “How do we know that there hasn’t ALWAYS been an ‘ozone hole’ over the Antarctic-and that it varies in size?”
    This was in the same sort of vein of investigation that I queried (with very good cause) the assumption that arctice ice is at an unprecented low level because we only record since 1979 and don’t consider longer cycles.
    This is a reply to my email-the preliminaries confirmed the assumption I made that we don’t know for certain, and then went on: (there then folows other informationI colected together at the time).
    ***
    “Thank you for your email. Here are some replies to the points you raise.
    1 Measurements of ozone over Antarctica started in 1956 from ground stations and show that levels were roughly constant until around 1980. The satellite record started in 1970 and has been continuous since 1979. The two records are entirely consistent with each other and with other measurements such as the vertical distribution of ozone measured by ozonesondes and upper air temperature and wind measurements. The length of geophysical records is an important consideration in their interpretation, and it is always important to see how consistent our understanding (theoretical and related measurements) of the current situation is with the long-term behaviour. In the case of the Antarctic ozone hole, there is additional overwhelming evidence that the combination of atmospheric dynamics and the atmospheric chemistry related to CFCs causes the annual decline in ozone each year. Basically we can see that the annual decline is cause by chlorine chemistry and we know that stratospheric chlorine comes principally from CFC which were not present, say, a hundred years ago. The evidence is very well documented in a number of places and I will not repeat it here. The question as to whether conditions in the past could have led to an ozone hole by a completely different mechanism is an interesting one, but it does not affect our confidence in the fact that CFCs are responsible for the current ozone hole.
    2. The new laboratory measurement of Cl2O2 by Pope et al has received a great deal of scientific attention internationally over the last year. As discussed by Pope et al., the analysis of the raw laboratory measurements is tricky and has uncertainties associated with it. Four independent laboratory groups are making new measurements of the process with different techniques and I anticipate that the results will be known in the next few months. In the meantime, careful analysis of existing laboratory and field measurements shows that either we are missing an important constituent which behaves like Cl2O2 or the new measurement is in error. Only time will tell which is right.
    3. To the best of my knowledge, Qing-Bin Lu was not involved in any way in the Pope et al. study. He/she was certainly not involved as an author and is not mentioned in the acknowledgements. My views on the atmospheric relevance of Qing-Bin Lu’s work (completely different to the Pope et al work) are best described in my comment on his/her Phys Rev Lett paper in 2001 published subsequently in that journal. I have seen nothing in subsequent publications by Dr Lu to change my view that the atmospheric significance of the processes under consideration is small at most. I agree fully with R. Muller’s comment on Dr Lu’s most recent paper.
    I hope these answers suffice.
    Yours
    (name deleted as it was a private email)
    Item 3) The following posts came from Watts up and I have collected them together as they are obviously relevant;
    Dr. Linwood Callis of NASA led an agency investigation of the causes of ozone fluctuations during the 1980s. As he told me: “The overwhelming portion of the ozone depletion in the 1980s was due to natural causes,” and the effect of CFCs “was really quite small — less than one-half of one percent.” (His paper “Ozone Depletion in the High Latitude Lower Stratosphere: 1979-1990″ appeared in the Journal of Geophysical Research, Vol. 96, No. D2, Feb. 20, 1991, pp. 2921-2937.) Callis went on to say that he thought that scientists blaming CFCs for ozone depletion were being “less than honest.”
    Another one bites the dust.
    http://ftp.vix.com/objectivism/Writing/RobertBidinotto/OzoneDepletion.html
    Item 4 Leif Svalgaard (13:18:35) :
    Ferdinand Engelbeen (11:24:06) :
    Is this not more a question of a less active sun in general, where the cosmic rays are inversely coupled to?
    Seems likely to me, but I need to see the original article. I have great ‘admiration’ for NASA’s ability to blow something out of proportion and label it as “New”, “breakthrough”, “important”, etc.
    dmdoug (11:37:22) :
    Is this caused by the shrinking heliosphere?
    No, the cosmic ray intensity now is not any larger than it usually is a every solar minimum. On http://www.swpc.noaa.gov/alerts/solar_indices.html look for Neutron Monitor % of background, Oct 24 100.0 %
    The ‘background’ is the normal long-term intensity when there is no solar modulation.
    Cosmic rays have always been around. So the ozone hole during the Maunder and Dalton minima [where many people (including the Heartland Institute representatives) claim less solar activity -> more cosmic rays -> LIA] should have been larger than now if the primary driver of Ozone hole size was cosmic rays. So, next month’s hole would not be the largest, unless, of course, helped along by CFCs.
    Item 5
    My daughter-in-law [Signe] had a review article in Nature a couple years back. They concluded:
    “Nature 441, 39-45 (4 May 2006) | doi:10.1038/nature04746
    The search for signs of recovery of the ozone layer
    Elizabeth C. Weatherhead & Signe Bech Andersen
    Abstract
    Evidence of mid-latitude ozone depletion and proof that the Antarctic ozone hole was caused by humans spurred policy makers from the late 1980s onwards to ratify the Montreal Protocol and subsequent treaties, legislating for reduced production of ozone-depleting substances. The case of anthropogenic ozone loss has often been cited since as a success story of international agreements in the regulation of environmental pollution. Although recent data suggest that total column ozone abundances have at least not decreased over the past eight years for most of the world, it is still uncertain whether this improvement is actually attributable to the observed decline in the amount of ozone-depleting substances in the Earth’s atmosphere. The high natural variability in ozone abundances, due in part to the solar cycle as well as changes in transport and temperature, could override the relatively small changes expected from the recent decrease in ozone-depleting substances. Whatever the benefits of the Montreal agreement, recovery of ozone is likely to occur in a different atmospheric environment, with changes expected in atmospheric transport, temperature and important trace gases. It is therefore unlikely that ozone will stabilize at levels observed before 1980, when a decline in ozone concentrations was first observed.
    Item 6
    (Some of this contains material that repeats the news source I quoted in Item 1)
    There are some big problems with the CFC-ozone causal link claimed by promoters of the Montreal protocol. There was a paper in Nature last year from NASA JPL that reported measured reaction rates for one particular chemical pathway to be much too slow compared with the assumed reaction rate that led to the predictions of ozone destruction rates from A-CFC’s.
    http://www.junkscience.com/sep07/Chemists_poke_holes_in_ozone_theory.htm
    Some of the quotes from the authors and other atmospheric chemistry/ozone experts are very enlightening. For example,
    “This must have far-reaching consequences,” Rex says. “If the measurements are correct we can basically no longer say we understand how ozone holes come into being.” What effect the results have on projections of the speed or extent of ozone depletion remains unclear.”
    “The rapid photolysis of Cl2O2 is a key reaction in the chemical model of ozone destruction developed 20 years ago2 (see graphic). If the rate is substantially lower than previously thought, then it would not be possible to create enough aggressive chlorine radicals to explain the observed ozone losses at high latitudes, says Rex. The extent of the discrepancy became apparent only when he incorporated the new photolysis rate into a chemical model of ozone depletion. The result was a shock: at least 60% of ozone destruction at the poles seems to be due to an unknown mechanism, Rex told a meeting of stratosphere researchers in Bremen, Germany, last week.”
    “Other groups have yet to confirm the new photolysis rate, but the conundrum is already causing much debate and uncertainty in the ozone research community. “Our understanding of chloride chemistry has really been blown apart,” says John Crowley, an ozone researcher at the Max Planck Institute of Chemistry in Mainz, Germany.”
    “Until recently everything looked like it fitted nicely,” agrees Neil Harris, an atmosphere scientist who heads the European Ozone Research Coordinating Unit at the University of Cambridge, UK. “Now suddenly it’s like a plank has been pulled out of a bridge.”
    But Montreal Protocolists continue to point to the ’success’ of the CFC-banning protocol as a blueprint for carbon dioxide controlling protocols. I guess it depends on your measure and definition of ’success’.
    ***
    Bill, sorry for the length of this post but I hope you find it of relevance. Now I make no claims either way ( I leave that to Qing Bon Lu whose research I quoted). I find the subject of theoretical interest because it deals with an ‘assumption’ that ‘we’ caused the hole. I have no particlar viewpoint other than to say it is nowhere as clear cut as you state, and our historic knowledge of any hole-man made or otherwisde-relies on very recent historical measaurement. I am just being a sceptic 🙂
    tonyb

  49. solar effect on O3 – reduction should be global and largest reduction at equator where solar inpact stongest.
    GCR – blatting the o3 bond. GCRs are modulated by 11 year solarcycle so ozone depletion should show this. Concentrated at poles by magnetic field??
    Calis predicted in 1987 that the ozone depletion had peaked see this interesting piece:
    http://www.ecosmagazine.com/?act=view_file&file_id=EC52p7.pdf
    ps. link http://ftp.vix.com%2Fobjectivism%2FWriting%2FRobertBidinotto%2FOzoneDepletion.html does not connect!
    Now of course shown not the case.
    Other theories of the time in this article.
    The hole appears at the time the stratospheric clouds appear @-80C. So it may have something to do with this. Dr. Plumb (in article) suggests a recent (i.e. recent to 1987) drop of 20C at 30km could be the cause.
    Unfortunately AMSU only goes back to early 90’s and I plotted only 25km height but here is a temp plot:
    http://img512.imageshack.us/img512/6769/amsua19982009.jpg
    If 25km is equiv to 30km then 2000 should have been large hole 2002 small hole and largest should be 2008. No time to check, unfortunately. But it does not seem to agree with the plots above.

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