Controversy over tropical ozone hole

Posted: October 1, 2022 by oldbrew in atmosphere, cosmic rays, opinion, ozone, physics, research
Tags: ,

Layers of Earth’s atmosphere

Have experts missed a huge tropical ozone hole that has existed since the 1980s? — asks Geographical. Or could it be more a question of definitions?
– – –
In July, an extraordinary research paper, documenting a huge, previously undetected ozone hole over the tropics, prompted a flurry of news stories.

Said to be seven times the size of the well-known ozone hole over Antarctica, the discovery is cause for ‘great global concern’, according to Qing-Bin Lu, a professor at the University of Waterloo, Canada, and author of the report.

His research suggests that, unlike the Antarctic hole, which only opens in spring, the tropical hole remains open year-round, putting roughly half the world’s population at higher risk from ultraviolet radiation.

Most surprisingly of all, Lu claims that the hole has existed since the 1980s.

However, the paper and the results it reports aren’t supported by all ozone watchers.

Some experts, including Paul Young, an atmospheric scientist at Lancaster University and lead author of the forthcoming Scientific Assessment of Ozone Depletion (2022), sponsored by the World Meteorological Organization and the United Nations Environment Programme, categorically refute Lu’s conclusions. ‘There is no tropical ozone hole,’ Young says. ‘If it was there, I will stick my neck out and say that it would have been found.’

So how can scientists have such different takes?

Some of the controversy comes down to the use of different definitions. On average, the concentration of ozone (a highly reactive gas composed of three oxygen atoms) in the ozone layer is 300 Dobson Units, which, when compressed to the atmospheric pressure at the Earth’s surface, would form a layer three millimetres thick.

The conventional definition of an ozone hole is when this concentration drops below 220 Dobson Units. However, Lu defines a hole as ‘an area of ozone depletion greater than 25 per cent relative to the undisturbed atmosphere (when there were no significant chlorofluorocarbons in the stratosphere)’.

Chlorofluorocarbons are man-made, ozone-depleting chemicals used widely since the 1930s, which contributed significantly to the Antarctic ozone hole but which are now largely banned.

‘No ozone hole over the tropics would be observed by the conventional definition of an ozone hole,’ Lu notes in his report, ‘as the total ozone over the tropics was above 220 Dobson Units even with a loss by 56 per cent.’

Full article here.
– – –
Paper: Observation of large and all-season ozone losses over the tropics (2022)


This paper reveals a large and all-season ozone hole in the lower stratosphere over the tropics (30°N–30°S) existing since the 1980s, where an O3 hole is defined as an area of O3 loss larger than 25% compared with the undisturbed atmosphere. The depth of this tropical O3 hole is comparable to that of the well-known springtime Antarctic O3 hole, whereas its area is about seven times that of the latter. Similar to the Antarctic O3 hole, approximately 80% of the normal O3 value is depleted at the center of the tropical O3 hole. The results strongly indicate that both Antarctic and tropical O3 holes must arise from an identical physical mechanism, for which the cosmic-ray-driven electron reaction model shows good agreement with observations. The whole-year large tropical O3 hole could cause a great global concern as it can lead to increases in ground-level ultraviolet radiation and affect 50% of the Earth’s surface area, which is home to approximately 50% of the world’s population. Moreover, the presence of the tropical and polar O3 holes is equivalent to the formation of three “temperature holes” observed in the stratosphere. These findings will have significances in understanding planetary physics, ozone depletion, climate change, and human health.

  1. oldbrew says:

    From a report in The Independent:

    In the past, the presence of chlorofluorocarbons (CFCs) was considered to be the biggest cause of ozone depletion. The 1987 Montreal Protocol, which banned them, has seen a major reduction in their use.

    But despite the global ban, the largest, deepest and most persistent ozone holes – over the Antarctic – were still observed in the late 2000s and in 2020-2021.

    “This was unexpected from any of the photochemistry-climate models,” Professor Lu said.

    A separate theory of ozone depletion, known as cosmic-ray-driven electron reaction (CRE), in which cosmic rays from space reduce ozone in the atmosphere, was first proposed by Professor Lu and his colleagues two decades ago.

    He told The Independent: “The observed results strongly indicate that both Antarctic and tropical ozone holes must arise from an identical physical mechanism, and that the CRE mechanism has exhibited excellent agreement with the observed data.”
    – – –
    Lu is arguing that climate science has been wrong all along about supposedly human-caused ozone.
    = = =

  2. […] Controversy over tropical ozone hole | Tallbloke’s Talkshop ( […]

  3. oldbrew says:

    What they said in 2001…

    Ozone Layer Burned by Cosmic Rays
    August 2, 2001• Phys. Rev. Focus 8, 8

    Cosmic rays may be enlarging the ozone hole.

  4. catweazle666 says:

    If this phenomenon has been in existence since 1980 and really is an the existential threat it and the polar equivalents are cracked up to be, why have we not been observing huge numbers of victims succumbing to whatever lethally unpleasant effects they’re supposed to produce?
    It’s a mystery….

  5. Saighdear says:

    Hmm, methinks it’s was all just the start: Tell people a lot of rubbish about something they can’t see or comprehend, but know a LITTLE ( being a dangerous thing) ….. and they’re OFF ! Bit between the teeth. Meanwhile back in the paddock, change the way things get done to suit some spurious agenda. Yes, I’ve read so much about it over the years, and like the similar acid rains over European forests, etc. …. And FORD encouraged us to get Aircon in our cars – “Free with the G Pack” so as volume turnover increased they became cheaper and a Must have. Like diesels for the City Plebs who would have been better on a Moped or early EV ( old milk float when they became available) and leave the Diesels for Commercial / INdustrial machinery.
    The Biggest Holes are emanating from the scientific community ( so called – sarc ). Just illustrating once again the gaping chasm between the city Know-nothings knowalls and the rest of the more productive Population trying everso hard against the tide of nonsense to provide Food and Goods to keep the Home fires burning. …. It’s Saturday night, my new weather station has just recorded a sudden 180 degree change of wind direction clocking 122 mph and then setting down again to around 10mph with the passing of a rain shower 3mm. and then I find these stories! Thanks for posting.

  6. Graeme No.3 says:

    I remember a friend at another company complaining about shipping lots of wood test panels back to Switzerland in the late 1980’s. The new weather resistant clear varnish on trial in Queensland had failed outdoor exposure in less than 12 months. The H.O. couldn’t believe the results as similar tests had shown no such problems after 3 years testing in Nigeria (and time in Florida), and 5 years outdoors in Europe. Once they had examined the panels H.O. decreed that in future all new products had to pass exposure testing in Queensland.
    It seems that Qld. had a very high UV level to go along with the tropical marine environment at the testing station. And that was before Global Warming.

  7. Curious George says:

    The danger of ozone holes is an increase of ultraviolet radiation at the surface. How come no one noticed it since 1980?

  8. Phoenix44 says:

    So cosmic rays make another appearance?

    And all that money we spent getting rid of CFCs was a total waste. What a surprise.

  9. oldbrew says:

    Quote from the paper:

    Indeed, there was a report called HIPERION published by the Ecuadorian Space Agency in 2008. The study using ground measurements in Ecuador and satellite data for several countries over 28 years found that the UV radiation reaching equatorial latitudes was far greater than expected, with the UV index as high as 24 in Quito. This Ecuadorian report concluded that O3 depletion levels over equatorial regions are already endangering large populations in the regions.
    – – –
    Quito is the capital city, at an altitude of 2850m.

    Another paper by Lu:

    Fingerprints of the cosmic ray driven mechanism of the ozone hole (2021)

    There is long research interest in electron-induced reactions of halogenated molecules. It has been two decades since the cosmic-ray (CR) driven electron-induced reaction (CRE) mechanism for the ozone hole formation was proposed. The derived CRE equation with the stratospheric equivalent chlorine level and CR intensity as the only two variables has well reproduced the observed data of stratospheric O3 and temperatures over the past 40 years.

    FIG. 1. The cosmic-ray-driven electron-induced reaction (CRE) mechanism of the ozone hole:9,12,21–24 Cosmic-ray (CR) driven electron-induced reactions of halogen-containing molecules (e.g., CFCs, HCl, and ClONO2) in polar stratospheric clouds (PSCs) result in the formation of Cl, ClO, CF2Cl· or CFCl2·, and Cl− ions. The Cl− ions can either be rapidly converted to reactive Cl atoms or react with other species to release photoactive Cl2 and ClNO2 in the winter polar stratosphere. The Cl, ClO, and CF2Cl· or CFCl2· can destroy the O3 layer in the polar stratosphere during winter; the photolysis of Cl2, ClNO2, and ClOOCl can also enhance ozone destruction upon the return of sunlight in the springtime.
    – – –
    This study* further predicts another minimum O3 hole to observe around 2025 ± 1 and another maximum O3 hole around 2031 ± 1.
    [*Fingerprints of the cosmic ray driven mechanism of the ozone hole]

    Around solar max (2025) and solar min (2031).

  10. oldbrew says:

    The Independent reported:
    In the past, the presence of chlorofluorocarbons (CFCs) was considered to be the biggest cause of ozone depletion. The 1987 Montreal Protocol, which banned them, has seen a major reduction in their use.

    But despite the global ban, the largest, deepest and most persistent ozone holes – over the Antarctic – were still observed in the late 2000s and in 2020-2021.

    “This was unexpected from any of the photochemistry-climate models,” Professor Lu said.

  11. Gamecock says:

    I wondered in the 1980s just whom was going to be harmed by UV in Antarctica. Few people there, and the few were bundled up quite well.

    I knew the principals at Dupont. They told me that they had the science that showed that Freon™ wasn’t harming the ozone. BUT, marketing told them to STFU. The science didn’t matter, they were getting crushed by the media. A media indictment for harming the environment doesn’t need facts. It was a business decision to not fight it.

    The conspiracy theory that the Montreal Protocols was a test run for the Global Warming scam is unlikely. It wasn’t intentionally an incremental start, but the UN et al certainly learned from it and it became the original global environmental action.

    The conspiracy theory that Dupont didn’t fight it because it allowed them to roll out more expensive replacement products is bogus as well. I know that for a fact, as I knew the people involved.

    After the Montreal Protocols, Dupont, as well as GE, drifted into a fascist relationship with the U.S. government. If government is going to control your business, it makes sense to form a relationship with them. You get to participate in the creation of controls, which allows you to design them such that COMPETITORS can’t comply. Monopoly makes you not care what government dictates, as you can just pass the cost on to your customers.

    A grand example of this perversity today is RPS, Renewable Portfolio Standard. Over half of US states have them. North Carolina requires 20% of a power company’s electricity to come from renewables. Which means that Duke Power, the monopoly provider, must do 20%. So Duke does this Kabuki Theater dance with the government and renewables. They’d rather not do it, because it is so nonproductive, but they don’t fight it, because they don’t want to appear to be anti environment, and they just pass the cost on to their consumers. They have a guaranteed rate of return, so they will never be stuck with the outlandish expense. The rate payers are.

  12. Saighdear says:

    Yes @ Gamecock, if I may, ‘…drifted into a fascist relationship with the U.S. government. If government is going to control your business, it makes sense to form a relationship with them. . ….. ‘ and all the rest but now it’s Covid or the coming TWIN demic , Net zero et al.. and the sheepl still don’t say it.
    For those of us who had an education, it was very difficult to unlearn the truth and learn the fake …. which must be true – cos everybody says so aand I must have gone stupid. and while I’m licking my terrible wounds, I am still fit tpo see and SAY ‘Look at the King’s ( !! – it is now – and he is as of this weekend’s News release from Buck P.) new clothes. He’s not just naked, but is he really the KING – his mother was our Queen yet served us. …. some contradictions in there – wot we’re all fed and accept. It’s no use all this stuff coming out now AFTER the horse has bolted and hoofed the shit around. “Suffer little children…..”

  13. oldbrew says:

    the largest, deepest and most persistent ozone holes – over the Antarctic – were still observed in the late 2000s and in 2020-2021.

    These were times, coincidentally or not, of unusually (in recent history) deep solar minima. As anyone can easily check, cosmic ray counts peak at such times…
    (see third chart down: ‘complete Oulu data’)
    – – –
    Sun Down: High-Energy Cosmic Rays Reach a Space Age Peak

    A prolonged lull in the sun’s activity has allowed energetic particles to penetrate the solar system with record intensity
    October 6, 2009

    When the sun is at a low ebb, the solar shielding that usually deflects cosmic rays from our neighborhood recedes, and a long dormancy such as the one at present is accompanied by a large swell in radiation.
    . . .
    “If you look back over the last 1,000 years, cosmic rays were actually on average much higher than they are during the 50 years where we have direct measurements,” he says. “Perhaps what we’re observing is something that’s more normal, and the space era has occurred when there was more solar activity, and so cosmic rays were excluded.”
    [bold added]

  14. oldbrew says:

    Gigantic Ozone Hole – 7 Times Larger Than Antarctica’s – Widens Over The Tropics

    The ozone hole narrative and the presumption that governmental policies are what determine how small or large the hole gets would appear to be analogous to the current climate debate and its connection to the governmental push to dramatically limit CO2 emissions.

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