Talk:Ozone depletion/Archive 1
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..links to the bottom (if the links are going to oppose something-- which they have every right do to-- it sort of makes sense to first present that which they oppose, I figured.) I also felt that it was strange to classify the prevailing scientific opinion as the "environmentalist position"... I suppose you might automatically classify as "environmentalist" all chemists and atmospheric scientists who believe in the damaging environmental effects of CFCs-- but such a definition seems rather circular.
Sorry, if it's indeed the prevailing scientific opinion it should be labeled that way. But even then, if scientists are divided on an issue, a pro-con division would be better than a scientists-sceptics division. As an educated layman, I know what the standard of scientific proof is, and if a public policy organization claims that a certain cause would increase the incidence a bad thing (like cancer), there should be evidence of this, not just predictions.
- There's nothing wrong with pro and con. I just wanted you to point out that both positions are scientific theories, not "environmentalist" or "anti-environmentalist" theories (which you did, so I apologize for beating a dead horse.) Some scientists who accept the CFC-theory on the basis of the evidence may drive to work in big gas guzzling trucks and hose their lawn with contraband DDT. The fact that environmentalists happen to agree with the scientific theory is relevant, but it does not define the theory (anymore than the fact that deodorant-can manufacturers probably agreed with the opposing side at the time makes Mr. Singer's theories the "Deodorant-can manufacturer" position.) I do think it's useful if it's made clear that one particular view is seen as the prevailing scientific view... This doesn't make the scientists on that side "right", but it helps explain why people (like government agencies) tend to come down on one side.
The articles on ozone and CFCs need data on measured UV radiation, incidence of cancer, ozone levels, and CFC levels. Then a hypothesis linking them. Then testing and confirmation of the hypothesis. Anything less than this is not science but advocacy. Agreed? User:Ed Poor
- I agree, but as you've seen, it's often in the interpretation of observed fact where problems appear. I don't know if any of us here have sufficient knowledge to prove or disprove any hypothesis, no matter how much information we're able to gather. For instance, I find string theory to be a very cool idea, and I can dig up facts and write articles about it. But in the end, I'm blah b;ah blash blah blah blah blah blha
I would like to mention some of Singer's points, as follows:
- The major public concern about a possible depletion of ozone comes from the fear that solar UV-B (280-320 nm) radiation reaching the surface will increase, typically by 10%.
- Yet UV-B intensity increases naturally by about 5000% between pole and equator; there is less ozone traversed when the sun is closer to the zenith (32).
- Hence a 10% increase at mid-latitudes translates into moving 60 miles (100 km) to the south, hardly a source for health concerns.
Would someone please least at least one scientist who supports the CFC-ozone-UV-cancer hypothesis? I already know that the UNEP, a public policy advocacy organization, believes in it. But does anyone know what scientific work they base their position on? Please name names of scientists and their university or other affiliation. User:Ed Poor
I did an Altavista search for "increasd UV radiation" and got Columbia University's web page. It looks pretty scientific to my, but I haven't double-checked their footnotes. Also the latest info cited is 12 years old. Here's a quote: User:Ed Poor
- Substantial reductions of up to 50% in the ozone column observed in the austral spring over Antarctica and first reported in 1985 (Farman et al 1985) are continuing (SORG 1990). Coupled with this there has been a statistically significant downward trend in wintertime total ozone over the northern hemisphere of about 2-3% per decade for the past 30 years, although summertime ozone levels have remained approximately constant (Frederick 1990). In its report in June 1990, the UK Stratospheric Ozone Review Group concluded that there are serious limitations in our understanding and ability to quantify ozone depletion at the present levels of contaminant release and in our ability to predict the effects on stratospheric ozone of any further increases (SORG 1990).
Increased UV has been measured at Earth's surface--notably in Toronto, and I'll have to see if I can verify my memory that the Chilean city is Punta Arenas. I changed the text accordingly: solid measurements exist, it simply isn't true to say "scientists have not measured" this.
- Yes, Punta Arenas. It's a high enough latitude that the increased radiation doesn't equal a huge risk yet--but it is exactly the evidence being asked for, of increased UV reaching Earth's surface because of ozone depletion. A lot of the relevant papers, unfortunately, are in Portuguese--is there someone here who can read that? A little quick work with Google got me Volker Kirchhoff as one of the people working on this. Vicki Rosenzweig
Moved the following pending source (I hope it's there, I believe you, Vicki!):
- Increased ultraviolet, presumably due to ozone depletion, has been measured in Toronto, Canada and in southern Chile.
If solid measurements exist, we should be able to find them this week. I'd be happy to see those measurements quoted and cited in the article.
Atmospheric scientist Fred Singer wrote (half a dozen years ago) that scientists had yet to see any increase of solar ultraviolet radiation at the Earth's surface. I'll wait a day or two and see if Vicki or anyone finds any more recent measurements before restoring the deleted text. User:Ed Poor
Okay, some quick Canadian references, with data from today (literally), 1993, and 1997:
- For current data, try http://woudc.ec.gc.ca/e/ozone/ozonecanada.htm
- "In 1993, the expected link between ozone depletion and increases in UV radiation at the surface was finally confirmed through the analysis of spectral data. The study, by Environment Canada scientists, has recently been extended to cover an 11-year period ending in 1996. It shows a positive trend of approximately 1% per year in the summer radiation at 300 nm." (From http://exp-studies.tor.ec.gc.ca/ozone/Summary97/Summary.htm, which also has a good color map comparing ozone levels over Canada in 1987 and 1997.) Vicki Rosenzweig
The web page you quote concedes that the scientific basis for the graph is "minimal":
- The accompanying graph shows how ozone has decreased from 1965 to 1996. It then compares, in a simplified fashion, what might happen if our current assumptions about ozone depletion are correct, and the Montreal Protocol and its amendments are fully implemented, with an alternative scenario in which concentrations of ozone-depleting substances remain unchanged at 1997 levels. Although the scientific basis for the graph is minimal, it does illustrate that evidence of a clear trend towards increasing ozone amounts may not emerge until after 2005 or 2010. In reality, however, such evidence may be delayed even further because compliance with the protocol may not be complete and there are still uncertainties in our understanding of the science. These uncertainties also make it difficult to predict confidently when ozone concentrations will finally return to natural levels. [1]
Also, the page mixes science with advocacy a lot. This makes it hard to read. While this doesn't disqualify it from being a wikipedia reference (i.e., I won't delete it), it's hardly satisfying to the interested layman.
I removed the following paragraph from the main page:
- In its report in June 1990, the UK Stratospheric Ozone Review Group concluded that there are serious limitations in our understanding and ability to quantify ozone depletion at the present levels of contaminant release and in our ability to predict the effects on stratospheric ozone of any further increases (SORG 1990).
I cannot make sense of this. What "further increases" are they talking about? And what does the "UV on biological systems" article have to do with anything? We are talking about ozone depletion. That reference could go into the UV article. AxelBoldt
Ed: In your overwhelming efforts to distinguish between NPOV and non-NPOV you seem to be taking a rather non-NPOV stance. For instance, "Some advocacy groups attribute a role to human-made substances" without explaining that these include scientists as well as conventional wisdom is no less non-NPOV than you think the statement: "Scientists attribute a role ..." is. Rather than upholding one position, you seem to be belittling another. Not a very NPOV thing to do. Danny
Sorry, if a scientist is a member of an advocacy group I guess I should mention that. How about, Scientist Joe Blow, member of advocacy group Chilly Breezes, supports the contention that..."
If, however, scientists are divided on an issue the wikipedia should say so and not accept uncritically claims by advocacy groups that their is scientific consensus. We already went through this on global warming, which I spent countless hours NPOV-ifying to take out pro-Kyoto bias.
State of the science
(William M. Connolley 14:09, 11 Aug 2004 (UTC)) In view of the changes around here, let me state my position on the science, which I will defend unto the death.
- Unlike attribution of climate change, there is no room for "reasonable doubt" on cfc's-cause-ozone-loss. It is proved beyond reasonable doubt.
- The observed ozone depletion is... observed. There is no room for doubt about that either.
Slightly off to the side, but since Ed keeps changing it it will keep coming up: ozone depletion means... depletion of ozone. The connection to skin cancer is important, but it isn't what OD means.
(William M. Connolley 14:25, 11 Aug 2004 (UTC)) Attempting to keep the discussion in one place re Ed's attempt to rescue Singer on Ozone hole...
Singer is, scientifically, a bad joke, and says nothing (on ozone at least) that is worth rebutting. He doesn't publish on ozone (because he has nothing scientifically valid to say). Hence scientists don't rebut him.
As for Ed's comments: since when has pointing out non-publication been an ad hominem?
But most of that stuff should probably migrate to the FS page anyway.
BTW Ed, I have an offer for you: you promise not to add any stuff by Singer for a month, and I promise not to add anything by any single named researcher you care to name. This won't be a problem for you, because of course Singer isn't a one-man-band and there are, of course, loads of other people you could be quoting from - yes?
Scientific evidence vs. rhetorical skill
I have a better offer. I'll put enough statements by Singer regarding ozone, that (combined with what you might call "real science") ought to provide enough rope to hang him out to dry.
- (William M. Connolley 15:53, 12 Aug 2004 (UTC)) No, thats not a better offer. My point is that Singer (and SEPP) is a one-man-band. Your point is that... you agree with me on that?
Like this:
- a statement by Singer in the 1990s that there was no CFC-Ozone link (which I'll try to dig up)
- a scientific paper linking CFC (which you probably have sitting on your desk!) comparing CFC emissions, or observed concentrations in the sky, to MEASURED amounts of Ozone in the sky.
If we can find a cause-and-effect relationship, let's put this in the article. Something like:
- CFC emissions were X tons per year in 1970, increasing steadily to X2 tons by 1990. During that time, ozone concentrations fell from A in 1970 to A2 in 1990.
- Since 1990, emissions dropped gradually to Y, and the ozone concentration recovered to B in 1995, B2 in 2000, and B3 in 2004.
If you want to defend science to the death, you'll consider my offer, won't you? --Uncle Ed 15:19, 12 Aug 2004 (UTC)
- (William M. Connolley 15:53, 12 Aug 2004 (UTC)) We already have the statement-cut-into-4-points. Those are enough to hang him. You have complained about those a lot already and removed them several times, but never settled down to answer them.
- If you mean his analysis of (1) CFCs deplete ozone; (2) ozone depletion increases harmful UV radiation; (3) increases in UV have been recorded at surface level, causing (4) more cancer, esp. melanoma -- then I don't think I'm the one who keeps deleting that. I want ozone depletion theory to discuss the causative links between CFC, ozone, UV radiation, and cancer -- because that's the justification behind the Montreal Protocol. I want Wikipedia to enable readers to decide for themselves if the science backs up the politics on that. And I can do this a lot easier with your help than without. --Uncle Ed 16:04, 12 Aug 2004 (UTC)
- (William M. Connolley 20:23, 12 Aug 2004 (UTC)) Nope, I mean the 1234 on the SEPP page.
(William M. Connolley 20:23, 12 Aug 2004 (UTC)) BTW, I'm fairly sure that your (3) and (4) are much more weakly evidenced (?) than your (1) and (2) - but its also the bits I know least about.
Talk from merged "Ozone hole" page follows below:
Please relate the ozone hole to increases in cancer, and provide figures. Otherwise, this article will be biased toward the environmentalist anti-CFC point of view instead of being neutral. User:Ed Poor
Here is some information I found on the web. Perhaps it can be added to the article: User:Ed Poor
External references:
The amount of ozone above a point on the earth's surface is measured in Dobson units (DU) - typically ~260 DU near the tropics and higher elsewhere, though there are large seasonal fluctuations. [2]
It's ironic that at ground level, ozone is a health hazard - it is a major constituent of photochemical smog. However, in the stratosphere we could not survive without it. Up in the stratosphere it absorbs some of the potentially harmful ultra-violet (UV) radiation from the sun (at wavelengths between 240 and 320 nm) which can cause skin cancer and damage vegetation, among other things.
The Ozone Hole often gets confused in the popular press and by the general public with the problem of global warming. Whilst there is a connection because ozone contributes to the greenhouse effect, the Ozone Hole is a separate issue.
The first global agreement to restrict CFCs came with the signing of the Montreal Protocol in 1987 ultimately aiming to reduce them by half by the year 2000. Two revisions of this agreement have been made in the light of advances in scientific understanding, the latest being in 1992.
However, unlike the sudden and near total loss of ozone over Antarctica at certain altitudes, the loss of ozone in mid-latitudes is much less and much slower - only a few percentage per year.
Many of these findings have since been reinforced by a variety of internationally supported scientific investigations involving satellites, aircraft, balloons and ground stations, and the implications are still being quantified and assessed.
I have found one website at NASA that list the ozone layer as absorbing 95-99% of UV radiation. It listed a study that claimed that since 1969, total worldwide stratospheric ozone had declined 5.5% which should led to an 11% increase in UV-B reaching the surface and a 20% increase in basal carcinomas and 30%increase in squamous-cell carcinomas[Graedel&Crutzen]. These are the most easily cured skin cancers and there is less evidence relating melanoma to UV-B exposure. The site also listed another article which pointed out that a 10% increase in UV-B could be achieved by moving 60 miles south from any location. S.F.Singer Ozone, skin cancer and the SST Aerospace America July 1994. S.Fred Singer is director of the Science&Environmental Policy Project. --rmhermen
- Thanks for the info. Now, for the hard part: adding that to the article. --User:Ed Poor
There are two problems with this article:
- Advocacy and science are mixed together and need to be separated. If there is a real connection between CFCs, ozone depletion and increased surface UV -- leading to more cancer cases -- let's document the science. Or at least quote some scientists.
- We need to reduce the overlap between the article and ozone depletion and CFC.
(William M. Connolley 19:47 25 Jun 2003 (UTC)) I've added links to the ozone faq - which everyone should read :-) - and Jon Shanklins Ozone page. I've removed some skeptical text *from certain places*. Now for some pontificating: there is no scientific doubt about the connection between CFCs and Antarctic ozone depletion. None at all (once you ignore far-out loonies). One way to see this is to look at the weakness of the doubts raised on the page: doubt number 1 is that when the satellite data was first processed, there was an artificial low cut-off, so the hole wasn't seen! This is feeble indeed (and I've added a note about it). *However* where there is room for doubt (IMHO) is the link between ozone depletion and biological effects. So if you want to be doubty, focus on that.
- Good for you. One sad consequeence of NPOV is that we spend far too much time on wacky lies shamelessly peddled by quacks in the pockets of corporations with vested interests. You can all quote me on that. -- Tarquin 20:39 25 Jun 2003 (UTC)
- I agree completely. However, in my edits, I did not want to remove the objections completely, because somebody would only reinstate them in the insidious form in which every mainstream and well-attested piece of science was attacked all the way through the article. I instead moved them instead into a separate section of their own, so that they get an airing as required by NPOV, but with suitable caveats about Dr Singer, because his credentials really are very poor. On the subject of credentials, I note that William M. Connolley (who further toned down the objections, which I welcome) is a scientist at British Antarctic Survey. Hopefully his viewpoint as expressed above will be given due weight. User:Ed Poor says above "Let's at least quote some scientists" -- well now we have one!
- --Trainspotter 11:20 26 Jun 2003 (UTC)
- I'm a scientist (I confess) but I claim no special credentials on the ozone hole: I'm only an informed layman on that (who happens to be able to walk down the corridor and ask two of the co-authors of Farman, Gardiner and Shanklin '85 what they think...). To be fair to EP, he was asking for the article to quote scientists who were involved in the research (William M. Connolley 11:48 26 Jun 2003 (UTC))
Dr. Connolley, please write from a neutral point of view when describing scientists with whom you disagree. If Fred Singer has said something which other scientists have contradicted, please point out the contradiction rather than saying Singer is wrong.
Otherwise, I'm going to start citing you personally as a scientist who disagrees with Singer, rather than letting you "contribute" to the article posing as a disinterested editor. --Ed Poor
Points for swiftness... However, you should be watching your own objectivity.
Anyway: I thought what I'd added was clear enough. I'll add some more to "beat it to death".
On second thoughts, lets try it here. I'm presuming that you object to the "controversial" bit, not the "percolate" bit. Singer says:
- "CFCs with lifetimes of decades and longer" this is not controversial
- "become well-mixed in the atmosphere" nor is this
- ", percolate into the stratosphere," nor is this, if you say "are transported" rather than percolate, S's own page says "Contrary to the claims of some skeptics, CFCs do indeed reach the stratosphere..."
- "and there release chlorine." Not controversial either.
So: could you please clarify what you are complaing about?
(William M. Connolley 09:51, 9 Oct 2003 (UTC)) No answer?