Talk:Ozone layer

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Questions about the ozone layer[edit]

Reading about ozone and the ozone layer in Wikipedia and other sources left a lot of questions to answer. So I ventured a bit farther in the field and gathered enough data about electromagnetic radiation (EMR), the properties of photons end the interaction between electrons and photons, especially in gases. My questions were not answerd by this, but I can formulate them more precisely,so here we go.Just a few for starters.

1. About ozone in the atmosphere. Above the region where the ozone layer is situated a lot of air is found and of course enough EMR with frequenties of UV or higher. So why no ozone is found there?

2. Ozone concentrations of up to 10 parts per million occur in the ozone layer, according to ENCARTA. O2 concentrations in the atmosphere is about 2 parts per 10 or 200.000 parts per million. So for every mol O3 ther are 20.000 mol O2. Why are there so few ozone molecules while there is EMR and O2 enough to produce a lot more ozone ?

F.pakker 15:31, 26 Mar 2004 (UTC)

  • 1: Maybe because ozone formation is slow? See ionosphere and you'll see various gases are energized above. Note the high temperatures reached up there. Above a certain point one gets oxygen plasma instead of ozone. (SEWilco 04:58, 16 Apr 2005 (UTC))
  • 2: Ozone-oxygen cycle observes the formation rate of ozone is limited by the UV energy. (SEWilco 05:00, 16 Apr 2005 (UTC))

  • 1: There isn't a lot of air above the ozone layer ... and it's very thin. Looking at the ozone-oxygen cycle, you'll notice that the formation of the ozone takes a collision of 3 particles and thus the formation rate is proportional to the third power of the air density, the disintegration of ozone takes only a collision of 2 particles and thus the rate should be proportional to the square of the density. Therefore the relative concentration of ozone should decrease with decreasing density, everything else being equal. Icek 21:46, 17 April 2007 (UTC)

what is ozone deflection? where does this name comes from? — Preceding unsigned comment added by (talk) 06:49, 2 October 2008 (UTC)

ozone deflection is when the particles from the sun deflect off of the layers of the atmoshpere. —Preceding unsigned comment added by (talk) 20:33, 28 October 2009 (UTC)

And that is a made-up answer. He probably misspelled ozone depletion. There's no such thing as ozone deflection. - M0rphzone (talk) 06:53, 27 April 2012 (UTC)

This page needs substantive revision[edit]

This page contained a number of scientifically incorrect statements. I've just corrected these, but I think the page could use a more substantive rewrite, focussing on the basic physics and chemistry of the ozone layer instead of on ozone depletion, since the latter subject has a page of its own.

--Rparson 22:04, 7 Jan 2005 (UTC)

I'm new to this wiki stuff, but can someone please correct this entry. The entire segment entered by "Barwick" is very POV, and if left on the page at all, it should be in a subsection of "Ozone depletion skeptics." Haroun Tazieff is an 80 yr old volcanologist with little experience in ozone chemistry. His opinions are fringe at best, wrong at worst. The entire entry about his work is not original, but simply cut and pasted from a conspiracy theorists webpage.

See: and

Thanks, Charles Irvine

CI, you are correct. Please revert Barwicks version to the one before it... see the discusssion at Ozone depletion where he has spammed the same nonsense in. William M. Connolley 09:59, 5 November 2005 (UTC).
Just removed the geocities stuff. Not a valid source. Find a peer reviewed source or leave it out. Vsmith 14:33, 5 November 2005 (UTC)
Thanks! Keep watching though... I doubt we're finished... William M. Connolley 15:44, 5 November 2005 (UTC).

Much better now[edit]

Nice job, William and SEWilco. I just deleted some of my old text which has been made redundant by your additions. I think there are other redundancies that could be cleaned up over time. Also, I suggest moving the figure at the head of Amount of Ozone down to Ozone depletion, where it is more relevant. --Rparson 11:13, 14 Apr 2005

(William M. Connolley 20:35, 15 Apr 2005 (UTC)) Would be fine by me. Its probably best to just do things like that, and back off if anyone complains, which in this case is unlikely.
I think the figure showing "ozone amount" belongs with "Amount of Ozone". "Ozone depletion" can use improvement, but without sucking in all of the main article on the topic. (SEWilco 05:47, 16 Apr 2005 (UTC))

Care to explain how the current "ozone depletion" isn't VERY POV also?[edit]

You claim my text was my personal opinion and trying to convince people of my point of view, then explain to me how the claim that the text saying current ozone depletion and "increase in Cl and Br lately is increased markedly due to the release of large quantities of manmade organohalogen compounds, especially chlorofluorocarbons (CFCs)" isn't VERY POV also?

Because its the dominant scientific opinion supported by a large amount of research.

There is absolutely NO scienific evidence that proves this, it is simply speculation based on a correlation between CFC's being used and a decrease in ozone. It would be almost as valid to say "Joe Smith was born in Argentina in 1965, and a few years later the ozone started getting thinner, therefore Joe Smith must be a witch who's putting curses on our ozone"

No, you're just making this up. There is plenty of research, and its cited in the ozone depletion article, which is where you should be having this conversation.

There are PLENTY of other explanations for the changes in the levels of ozone, one of which is the fluctuation in natural greenhouse factors (C02, and others including water vapor which has 3 times the greenhouse effect of C02) over time, resulting in an increase (or decrease as they get lower) in earth surface temperatures, which also means that less heat escapes to the stratosphere, thereby cooling it.

I'm sure you're all familiar with this graph from Clearlight File:Http:// Example of regional variations in surface air temperature for the last 1000 years, estimated from a variety of sources, including temperature-sensitive tree growth indices and written records of various kinds, largely from western Europe and eastern North America. Shown are changes in regional temperature in ° C, from the baseline value for 1900. Compiled by R. S. Bradley and J. A. Eddy based on J. T. Houghton et al., Climate Change: The IPCC Assessment, Cambridge UniversityPress, Cambridge, 1990 and published in EarthQuest, vol 5, no 1, 1991. Courtesy of Thomas Crowley, Remembrance of Things Past: Greenhouse Lessons from the Geologic Record

Sigh again. That is the good old schematic from the IPCC FAR. Things have moved on somewhat since then. William M. Connolley 15:46, 5 November 2005 (UTC).

If we were able to measure the level of Ozone as far back as 1000 AD, I would be willing to bet that the largest decrease in stratospheric temperature was around 1000 - 1400 AD, and the largest (perhaps larger than today) decrease in the level of ozone would ALSO be from 1000 - 1400 AD. Similarly, the largest incerase in stratospheric temperature would probably be around 1400 AD to 1950 AD, also with the largest increase in the level of ozone in the stratosphere.

But since we can't thats just idle speculation.

Now, just like the "manmade CFC's are the devil" argument, we can't scientifically measure either of them, and therefore you've got two choices: One, put NEITHER of them on the page or Two, put BOTH fo them on the page

Three, make you see sense, Four, keep reverting your nonsense. Sigh. William M. Connolley 15:44, 5 November 2005 (UTC).

Barwick 15:53, 5 November 2005 (UTC) WMC: You're going to have to do more than "it's generally accepted today"... 150 years ago it was generally accepted that it's ok to have blacks as slaves, that doesn't mean it was right. Today it may be "generally accepted" that manmade CFC's are the devil (after all, when the media and universities force that down our throats from the time we're born, what else CAN we believe?)

Anyone else care to chime in with something scientific, and not an "appeal to authority" like WMC continues to do?

Scientific. Tests have shown that ozone is broken down into oxygen when exposed to chlorine, which works as a catalyst. Molecular theory supports this. Chlorofluorocarbons act as a delivery system for chlorine, as they rise into the stratosphere and are broken down into their base components. Chlorine is thus introduced into the stratophere.
CFCs upset the balance of ozone and oxygen and cause ozone to be broken down faster than it can be formed. Science. What's the problem? -- Ec5618 16:09, 5 November 2005 (UTC)
Sigh. First off, you're dead wrong: wikis policy *is* to report the current consensus. If you have a personal pet theory that through sheer brilliance overturns the accepted wisdom... it doesn't belong here. As it is, you have a pile of nonsense, which also doesn't belong. Secondly, trying to introduce strawmen like "CFCs are the devil" may work in playground drebates, but not here. We've seen it all before. As for science: please continue the discussion that you've wimped out of over at ozone depletion. William M. Connolley 16:04, 5 November 2005 (UTC).

Barwick 16:18, 5 November 2005 (UTC) Ec5618: Had you been paying attention, you would have seen that I'm not disputing that the ozone is broken down by these chemicals, I'm disputing that MANMADE SOURCES are the primary cause. NOBODY can show ANY scientific evidence that it is.

No, there is plenty of evidence, what you mean is you haven't read it. Go to ozone depletion which lists it, and where this talk should be. Or read the 2002 ozone assessment: William M. Connolley 16:59, 5 November 2005 (UTC)

Sorry, didn't see any evidence proving that the miniscule amount of manmade CFC's that reach the stratosphere are the PRIMARY CAUSE of the ozone depletion, simply another "correlation equals causation" argument is presented.

And the exact opposite to your claims is posted in another scientific article:

It is generally agreed that natural sources of tropospheric chlorine (volcanoes, ocean spray, etc.) are four to five orders of magnitude (1,d000 to 10,000 times) larger than man-made sources - Maduro, R. A.; Schauerhammer, R. The holes in the ozone scare. Washington, DC: 21st Century Science Associates; 1992.

You seem to be having problems telling "science" from "popular press"; your article falls into that category. The trop chlorine stuff is in the FAQ, of course: volcanoes, ocean stray et produce *soluble* chlorine that never reaches the stratosphere; whereas CFCs do get to the strat and there release chlorine. William M. Connolley 10:00, 6 November 2005 (UTC).

Barwick 16:40, 7 November 2005 (UTC) WMC: that's really interesting how you KNOW that no chlorine from natural sources reaches the stratosphere.

Dr. Ken Kubin, Assistant Professor department of Geology and Geophysics, University of Hawaii - "One final point that is probably worth noting is that it is important to remember that our monitoring of the exact nature of the ozone layer has only begun recently, and 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."

Similarly, out of the 600,000,000 tons of natural chlorine sources that enter the atmosphere, do you think that even .01% of that MIGHT reach the stratosphere, break down, and then stay there stored in the form of inorganic chlorine reservoir molecules, until they break down again and are either removed, or again become another inorganic reservoir molecule in the stratosphere? Or do you think that the filtering mechanisms are that good to remove every single possible source of natural chlorine from the atmosphere, before it reaches the stratosphere?

I don't care even what chemicals we find in the atmosphere, we could find one billion tons of CFC's there, and only one million tons of organic/inorganic chlorine compounds, but if only .000001% (10 tons) of them break down into chlorine on a yearly basis, and .1% (1,000 tons) of the other compounds break down into chlorine, then which of these two is causing the majority of the breakdown of ozone?

please provide some evidence for your assertions. No scientist denies that there is a small component to stratospheric chlorine from natural sources. However there are plenty of studies based on observations and modelling which show that the most important source of chlorine in the stratosphere is from CFCs. eg. Schauffler et. al., 2003 who made measurements in the artic winter of 2000 and found that "CFCs were the largest contributors to total organic chlorine (55–70%)". Please provide some evidence to support your ideas not idle speculation. Anyone can pull numbers out of a hat as you have.--NHSavage 22:38, 7 November 2005 (UTC)

Relevant to this discussion but missing are some questions about science and politics. First thing is why are hCFCs any safer? If we stipulate that CFCs are bad, we must continue logically to conclude that hCFCs are bad. The molecules are identical except for a little bit of Hydrogen added. Denying that these new molecules are as dangerous as the old is illogical. In fact the overall costs associated with these new refrigerants are much higher. The older CFCs are not as acidic; these new hCFCs require more robust seals. Many refrigerating systems are being scrapped or refitted(if feasible) to accommodate this acidic condition. Then there is the efficiency factor. Since the hCFCs are less efficient, there is a correspondingly greater input of energy to achieve the same output as measured in tons of ice per day. Pollution and cash outlays increase as output efficiency decreases. I have read some accusations about the patents on these chemicals(and PCBs) and the vigor of the debate being related. If anyone has access to the dates of these patents please share them.

Don't quote me on this (rparson will know for sure) but I think that HCFCs are less stable and so break up faster and so don't cause the same probs in the strat. William M. Connolley 22:56, 27 February 2006 (UTC)
WMC is correct. The lifetime of HCFCs in the troposphere is much shorter, so a far smaller percentage of the chlorine atoms reach the stratosphere. Therefore they do destroy much less ozone than CFCs. However they are also being phased out as they can still destroy statospheric ozone. The main tropospheric removal processes for these compounds are reaction with the hydroxyl radical and photolysis.--NHSavage 23:08, 27 February 2006 (UTC)
A further point: the major substitutes for CFCs are not HCFCs, but HFCs (hydrofluorocarbons) which contain no chlorine. E.g. in the US, the mandated substitute for CFC-12 in auto air conditioners is HFC-134a. HCFCs are only being used as temporary substitutes in some applications where the transition to chlorine-free substitutes is more difficult. --Rparson 16:20, 28 February 2006 (UTC)

Chapman mechanism etc[edit]

Would it make sense to merge the page on Ozone-oxygen cycle to here? I am not very happy with that page - too small really and does not really to my mind get across the essentially cyclic nature of the Chapman cycle. It would be nice to include the standard exercise calculating the expected ozone concentations which one gets from the Chapman cycle (time to dig out some old notes...) and explain that this concentration is wrong because of the catalytic destruction reactions. These could then be listed.--NHSavage 21:55, 11 March 2006 (UTC)

Seems sensible to me. That article always seemed to be something of an outlier. BTW, I haven't ever seen it referred to as the "ozone-oxygen cycle" anyway, it's always been "Chapman Mechanism" or "Chapman Cycle", but that just might reflect the sources that I tend to read.--Rparson 03:20, 14 March 2006 (UTC)

More details requested[edit]

I'd like to see more details (numbers) on what happens in the ozone layer. Specifically:

  • The article says that the ozone layer does not occur higher because the oxygen is ionized. Why does it not occur lower (this may have been answered already; I'll have to look again more closely)? How much of the ionization is due to UV?
  • Does UV have some unusual affinity for O3, as opposed to O1, O2 or N? We have an entire atmosphere worth of oxygen molecules. Can we get some figures on how much UV is stopped by the ionized oxygen, etc.?
  • The idea behind natural selection is that beings adjust to their environment. Is there any reason to believe that this would not happen with increased UV? Note, I'm not asking whether we would like it or not. :) I've also seen mention that suntan lotion may be responsible for some skin cancer, along with the fact that we apparently made do without suntan lotion for many thousands of years.
  • What percentage of total UV is filtered out at each step? If the amount of ozone would only be a few millimeters thick at sea-level, then it seems like ozone alone would not catch much.

--Scott McNay 23:33, 12 March 2007 (UTC)

I can give partial answers to 2 of your questions:

  • I think the ozone layer has got a lower limit because there isn't enough atomic oxygen in the troposphere, because there isn't enough UV radiation to create it, because this UV radiation is blocked by the ozone layer.
  • Evolutionarily you would probably see the same thing that you already see nowadays in native populations (i.e. living there for many millenia) of high-insolation countries vs. low-insolation countries: The skin will darken. Of course that doesn't take into account changes in lifestyle, sunscreen etc. Icek 06:49, 18 April 2007 (UTC)

Icek 06:49, 18 April 2007 (UTC)

Please somebody explain this to me.[edit]

The article doesn't give the "thickness" (that is, distance from bottom to top) of the ozone layer. This link from Caltech gives information that I would like to see explained in the article. -- 09:09, 29 March 2007 (UTC)

Its not a very good answer. Thats the thickness it would have if it were just a layer of pure ozone (at SLP?). The thickness of the atmos layer that ozone occurs in in is ?30 km? William M. Connolley 09:21, 29 March 2007 (UTC)

State of regulation on bromofluorocarbons[edit]

Bromofluorocarbons, which besides CFC's also have high ozone depletion value, have not been described, in regard to regulation (by industrial and developing countries). As besides CFC's this too has extremely high ozone depletion value it should be described. Besides this, there should be a list or reference in what products CFC's and bromofluorocarbons are present (as still sold in developing countries). KVDP 13:06, 30 Mar 2004 (UTC)

Why does it exist?[edit]

The article mentions that "stratospheric ozone is produced by solar UV radiation", but that's the extent to which it's discussed. Could a knowledgeable person write a section explaining why the ozone layer exists? (Prompted by a short unsigned question over at Talk:Ozone depletion.) Tempshill 16:37, 23 May 2007 (UTC)

There used to be a section on this, but some vandal deleted it way back when and it was never restored. I've put it back in.--Rparson 21:36, 24 May 2007 (UTC) (talk) Sunlight splits oxygen O2 into O1 and O1. These O1 particles combine with other O2 particle to form O3 (ozone) which is inherently unstable and breaks down quickly. Sunlight continually replenishes the ozone, except during polar winters when sunlight is absent.

The maximum chloroflurocarbon (Freon) detected in the 'Ozone Layer' has bee about five cubic millimetres per thousand cubic kilometres - equivalent to nothing! Freon is heavier than air and iron - it falls downwards.

The DuPont company did not want competitors to make Freon after the patent expired and paid for the Montreal process to ban its own product. Consumers were forced to buy the new replacement refrigerant.

The Ozone Layer does not prevent the type of ultraviolet radiation that causes skin cancer. The ozone hole was detected before DuPont invented chlorofluorocarbons. It will occur forever. — Preceding unsigned comment added by (talk) 20:45, 6 January 2018 (UTC)

why is no one paying attention to the hole in the ozone layer anymore?[edit]

why is it not as much of an issue as global warming? AbsoluteZero255 18:48, 25 October 2007 (UTC)

The usual answer to "why" is "money". But the article needs sources which state why before the article can state why. (SEWilco 19:10, 25 October 2007 (UTC))

Because Gore wouldn't get a Nobel for that —Preceding unsigned comment added by (talk) 15:17, 12 December 2007 (UTC) this means the ozone layer is tres inportant —Preceding unsigned comment added by (talk) 18:21, 19 May 2008 (UTC) in our earth ozon layer is more edfdfected to people —Preceding unsigned comment added by (talk) 17:08, 10 May 2010 (UTC)

UV absorbtion properties[edit]

Hi, I came to this article with a question about the ozone layer and it wasn't answered here at all. I'm trying to understand how the ozone layer acts as a UV shield. The article explains that the ozone layer blocks '93-99% of the sun's high frequency ultraviolet light' but my question is, how? What is occurring? It explains in the article the process of UV light striking oxygen and producing ozone, which off-hand sounds as if it is the oxygen itself that is doing the blocking and the ozone is just a by-product of that reaction. I see words like 'absorb' and 'screened' but there is no actually explanation as to what the ozone is physically doing. Why is ozone so good at 'absorbing' and 'screening' UV? There isn't an explanation in the whole article. (talk) 13:40, 8 September 2008 (UTC)

In general, electro-magnetic radiation is absorbed by matter when the energy of the EMR photon is used to push electrons away from the nucleus of its atom. This can only happen if the difference between the old energy of the electron and the new energy of the electron, and the energy of the photon are exactly equal.
Electrons have different energy "levels" to jump to based on their position near other particles, and they can never be in between these energy levels (imagine your car could have the amount of kinetic energy to be traveling 10 MPH, or the amount of energy for 22 MPH, but never 13MPH or 28 MPH). So an electron in any given situation will be able to absorb some wavelengths of light but not others, based on whether there is a jump available to a higher amount of energy or not (following the analogy above, if a photon hit your car with the amount of energy that is the difference between 10 MPH and 22 MPH, your car could start zooming at the higher speed, but if it were carrying the amount of energy equal to the difference between 10 MPH and 28 MPH, your car could not "catch" that energy and change speed). It so happens that in ozone, the electrons in the molecule have two amounts of energy possible that are the same amount of energy apart as that contained in a UV photon. Electrons in other molecules may not have two different levels of energy that are that difference from each other, so they could not absorb a UV photon. They could absorb a different color of light, though, if that color photon had the amount of energy that corresponded to the difference between two of their energy levels.

HeyRobbie (talk) 19:01, 8 July 2013 (UTC)


I am not very educated and some articles probably have already answered my question. Do we have the technology yet to replenish the ozone layer? If so, are we doing it or the price is too expensive to do so. —Preceding unsigned comment added by (talk) 05:49, 27 September 2008 (UTC)

ozone layer in stratosphere[edit]

I was wondering, why is the ozone layer up in the stratosphere while ozone is heavier than normal air, I'd say the normal air should "float" on the ozone layer. of course, that wouldn't be healthy, but that's not an answer.

question about the depletion[edit]

i wanted to know that since all the major developed countries release more amount of cfc then why the ozone layer of antarctic deplets and why not the ozone layer above that particular country? —Preceding unsigned comment added by (talk) 18:22, 27 February 2009 (UTC)

CFC's are well mixed William M. Connolley (talk) 21:59, 27 February 2009 (UTC)
and the higher depletion at the poles is due to concentration of ODS by certain wind patterns and the faster chemical reactions that can occur on ice crystals.HeyRobbie (talk) 19:03, 8 July 2013 (UTC)

Sweden the first to ban aerosols? January 23, 1978?[edit]

Is there any proof of this claim?

As per talk pages here and here, according to the Senior Registry Clerk at Sweden's Ministry of the Environment, The ban against CFC in aerosol spray came in to force 1st January 1989. 1 Currently (as of 2007), CFC is regulated under a newer ordinance 2.

Having seen mention of a 1979 ban at the EPA's website and the Stocholm Convention's website, neither providing a date or scope of the mentioned ban, I can only speculate. Whatever it was, it doesn't appear to have been written into Sweden's law. Kentholke (talk) 16:31, 10 March 2009 (UTC)

UPDATE: - The EPA has informed me that they cannot locate any information within their main information storage center as to Sweden's ban other than the press release. Details of the email are here. I'm removing the reference to Sweden having enacted their ban in 1979 from this article for now. Kentholke (talk) 20:59, 11 March 2009 (UTC)

ozone layer[edit]

I think the ozone layer contains relatively high concentrations of ozone(03). this layer absorbs 93 - 99 % of the suns powerfull rays

amawee —Preceding unsigned comment added by (talk) 15:22, 29 March 2009 (UTC)

very poor graph[edit]

What's with the inclusion of the graph TOMS_Global_Ozone_65N-65S.png? OK, it demonstrates an observed ~5% depletion on equatorial ozone as measured in Dobson Units over a 23 year period, but it's also a lesson from misrepresenting statistics 101. The vertical component wildly misrepresents the seasonal variation, as it represents approximately 1/8th of the axis as measured from 0 DU, and it gives no indication of any error margin given by the measuring apparatus. In fact, documentation available at the source [1] seems to indicate a minimum standard deviation of 2%, which is a significant portion of the area of the graph as depicted. I can understand why this information is not represented in the graph, as it is a small part of a greater body of information, however it is not presented with the appropriate caveats here.

While I have no doubt that it represents significant data, I believe that it is wildly misrepresentative when presented out-of-context in this manner (talk) 04:45, 12 May 2009 (UTC)

Gave it a few days, no-one cares. Removing the graph, as the easiest fix. (talk) 04:08, 17 May 2009 (UTC)
Looking at this article I think the graph is perfectly appropriate, most WP users who can read a graph understand that the axes do not necessarily cross at the zero point and a graph without that would be barely readable. Plus the extent of the seasonal variation is far greater than the statistical error and the decline is larger. I'm restoring the graph as illustrating variations in ozone over time as it certainly adds to the article.Stub Mandrel (talk) 19:14, 19 May 2016 (UTC)


I am puzzled about CFCs and HFCs causing ozone depletion and hope someone will response to my points. According to wikipedia, those chemicals' molecular weights are heavier than air, so how can they rise into the ozone layer and deplete it? As a heavy equipment mechanic who performs air conditioning work, I have found and have read that when using a "freon" leak detector, one must always place the meter underneath the suspected leak point to measure any "freon" escaping, and that placing the detector above the point will not trigger the meter, because the CFCs and HFCs are heavier than air. OK, if that is so, and the ozone layer allows only a small amount of UV light to strike earth's surface, I can understand that small amount of UV will break down those chemicals at ground level causing chlorine to be released. Now, according to wikipedia, the atomic weight of chlorine is heavier than air. So how can this chlorine rise eight miles into our atmosphere to deplete the ozone layer? An educated reply would be greatly appreciated.Chadjessup (talk) 18:41, 4 September 2010 (UTC)

those chemicals' molecular weights are heavier than air, so how can they rise into the ozone layer and deplete it - err, pause to think for just a moment. Are you also puzzled by the fact that the major constituents of the atmosphere - O2 and N2 - have different weights but don't separate out under gravity? If not... why not? Indeed, why aren't you puzzled that the minor consitiuents - which includes heavy noble gases - don't separate out. Pause to think about this for just a little while before reading Ozone depletion#Misconceptions about ozone depletion. William M. Connolley (talk) 19:16, 4 September 2010 (UTC)
Just because a gas molecule is heavier in atomic weight than ambient air doesn't mean that it cannot disperse due to diffusion, wind and natural air movement. It can't separate out because the effect that gravity has on gas molecules is negligible. Gas particles naturally diffuse through the air just like other fluids (gases and liquids are fluids). - M0rphzone (talk) 07:05, 27 April 2012 (UTC)
HFCs are substitutes for CFCs and HCFCs; they do not cause ozone depletion. However they do cause global warming. HeyRobbie (talk)

"Ozonosphere" ??[edit]

I noticed a new term; "ozonosphere." In fact, Wiki redirects it to here. I wonder if it's legit. Googling around, it does seem to be in a few dictionaries. Yet the term in nowhere in any of say, Robert Parson's four 1997 Ozone Depletion FAQs: . Nor is the term used in this article.

My quick search I did not notice the term in any peer reviewed papers. So, due to the remaining controversial political arguments on this topic, I wonder if the term was invented with an agenda. ("Science is actually part of The Great Evil Liberal Conspiracy Plot!") Thoughts?
-- (talk) 01:50, 4 May 2012 (UTC)Doug Bashford

UV and unexposed life forms in seas[edit]

Hello, the article states that "...medium-frequency UV, which potentially damages exposed life forms on Earth." I suppose the exposed life forms discussed are mainly life forms on land. How do plants on land react to excessive UV? Ozone was a prerequisite for life to extend to land, but would marine life forms be safe from UV if there were no ozone layer? I believe there were cyanobacteria before the ozone layer had developed. --Hartz (talk) 16:30, 16 October 2012 (UTC)

Hartz - the ozone layer could not have formed before the evolution of photosynthesis, because this process caused the large amount of oxygen currently found in the atmosphere to arise. The molecular oxygen is necessary for ozone to be formed by UV radiation. So life clearly preceded the ozone layer by more than a billion years. Water does scatter UV radiation effectively, so very little penetrates more than a meter into the sea. However, the fact that UV can severely limit survival on the surface doesn't mean that no individuals at all would survive, and for rapidly reproducing, unicellular life forms UV probably wouldn't kill absolutely everything. In fact the higher rate of mutation due to UV radiation may have sped up evolution, while at the same time limiting the total biomass possible on the surface. HeyRobbie (talk)


you should add a nice picture like that:

Sources of Greenhouse gases and their reaction with the ozone-layer; NOx, SOx can arise from combustion processes

if you find errors, please contact me, I will improve it.--Smiles :( :\ :o :() (talk) 13:04, 8 April 2015 (UTC)

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A bit confused - the article appears to have been the 'article for improvement' a day short of three years' ago, but has its time come again? I've restored a graph removed in 2009 for what I think appear to be spurious reasons and added a note on how the ozone layer affects UV astronomy as my first contribution to the AFI project. Stub Mandrel (talk) 19:21, 19 May 2016 (UTC)

I find this weird as well. --BabbaQ (talk) 23:46, 20 May 2016 (UTC)

Ozone layer HELP![edit]

so in school i was picked to do a science presentation on the ozone layer with two of my friends but I'm still struggling a bit Pls post some articles that are explained so a child can understand easily thx! :DAjijola (talk) 16:11, 13 September 2017 (UTC)ME!


Chlorofluorocarbon molecules are 4-8 times heavier than air but we are told they rise into the upper atmosphere. How? Does helium ever sink towards the Earth?

The miniscule amount of Freon in the upper atmosphere is due to vulcanoes and escapes from aircraft.

I once wrote an article for a newspaper confessing that I had personally destroyed the entire Ozone Layer over Australia because I used a small aerosol can of Freon, as an electronics technician. The truth is that the Freon immediately fell downwards where soil bacteria digested it within a few weeks. — Preceding unsigned comment added by (talk) 20:55, 6 January 2018 (UTC)

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Response to: Magic![edit]

Actually, this question has been thoroughly and exhaustively answered. One only needs to conduct a quick google search to find the answers. For ease of access, here is the question answered in the World Meteorological Organization 'Scientific Assessment of Ozone Depletion: 1994', "Although the CFC molecules are indeed several times heavier than air, thousands of measurements have been made from balloons, aircraft and satellites demonstrating that the CFCs are actually present in the stratosphere. The atmosphere is not stagnant. Winds mix the atmosphere to altitudes far above the top of the stratosphere much faster than molecules can settle according to their weight. Gases such as CFCs that are insoluble in water and relatively unreactive in the lower atmosphere (below about 10 kilometers) are quickly mixed and therefore reach the stratosphere regardless of their weight. Much can be learned about the atmospheric fate of compounds from the measured changes in concentration versus altitude. For example, the two gases carbon tetrafluoride (CF4, produced mainly as a by-product of the manufacture of aluminum) and CFC-11 (CCl3F, used in a variety of human activities) are both much heavier than air. Carbon tetrafluoride is completely unreactive in the lower 99.9 percent of the atmosphere, and measurements show it to be nearly uniformly distributed throughout the atmosphere as shown in the figure. There have also been measurements over the past two decades of several other completely unreactive gases, one lighter than air (neon) and some heavier than air (argon, krypton), which show that they also mix upward uniformly through the stratosphere regardless of their weight, just as observed with carbon tetrafluoride. CFC-11 is unreactive in the lower atmosphere (below about 15 kilometers) and is similarly uniformly mixed there, as shown. The abundance of CFC-11 decreases as the gas reaches higher altitudes, where it is broken down by high energy solar ultraviolet radiation. Chlorine released from this breakdown of CFC-11 and other CFCs remains in the stratosphere for several years, where it destroys many thousands of molecules of ozone."

The more you know... — Preceding unsigned comment added by Microscone (talkcontribs) 15:09, 22 January 2018 (UTC)