Could a Paris agreement on climate change be like the Montreal Protocol on CFCs?

For those who don’t know, the Montreal Protocol was an agreement between nations to limit, and in some cases end, the production of chlorofluorocarbons (CFCs),  gases used in hairsprays, insulating foam and refrigerators. You can find all about it in Wikipedia, though my usual caveat about that source applies here too: the article is written from the point of view of someone for whom the whole issue is well and truly settled.

A short summary is that a couple of scientists proposed in the early 1970s that these gases could have an adverse effect on ozone in the atmosphere, and a decade or so later another team of scientists pointed out that there was a ‘hole’ in the ozone over Antarctica. That seemed  verification of the original theory, and the first group of scientists got the Nobel Prize. Not only that, because ozone protects plants and animals from ultraviolet-B radiation, which can lead to skin cancer, there was quick agreement that the CFCs should be phased out, and to a large degree they have been.

In consequence the Montreal Protocol has been hailed as the best example of international co-operation, and the kind of model that that should be seen as the basis of any agreement on ‘combatting climate change’. Since I have been afflicted with skin cancers of various kinds for the part thirty years, I felt at the time that this was a good thing. I should add that I had a query about the link — a very ordinary query. That was, how did we know that the hole was caused by the CFCs? Or, more precisely, how did we know that the hole was new? No one had looked for a hole before‚ indeed no one had looked very hard at ozone anyway. What if the hole had always been there? How would we know?

At the time I was involved in research assessment and funding, and this was the kind of question that is almost basic in considering any request for money. No matter, my interest was purely academic, and no one asked for money for us, for any investigation into CFCs and ozone — at least, not one that involved me as the chairman.

The Protocol came up again in the 1990s, and especially in the first decade of the 21st century, as the right way to deal with global warming, or what became called ‘climate change’, when warming seemed to have stalled. George Monbiot of the Guardian, if memory serves, put this forward at around the time of the Copenhagen meeting, and I’ve seen similar references more recently.

At first glance, it seems a sensible idea, but closer inspection makes you wonder. First of all, though there was a great fuss about it from manufacturers of the CFCs in question, it appears that the patents (for freon, for example,) had expired, and the new non-ozone-threatening gases were more expensive anyway, which meant that everything would cost more, and manufacturers would in the long run make more money. Since the USA led the charge to abolish the old CFCs, there is a certain congruence in that account of things.

Second, the ‘climate change’ issue is much more complex, and of course vastly larger in its reach.  Not only that, there are substantial differences in perspective across the world, not only between developing and developed countries, but India and China versus the USA and the EU. And, dare I say it, the science of climate is not at all settled, with carbon dioxide emissions continuing to rise but temperatures falling and rising without any apparent connection with CO2. Politically, it is as though there are two different worlds, one where various elites  and the media sympathetic to them continue to expatiate about the danger, the urgent need, the great necessity, and so on, while the mass of citizens, inured to this hyperbole, get on with their lives and basically ignore the fuss.

If that were not enough, it now seems that ending the production of those nasty CFCs didn’t actually close the ‘hole’. It was not exactly a hole anyway, but rather a thinning of the ozone layer. An article by sceptic Steve Goreham, which you can read here, uses NASA data to suggest that there is still substantial thinning. The image looks like this. Why?


Goreham’s article was picked up by Anthony Watts, and republished on WUWT. Watts added a most intriguing diagram, which follows.


‘Ozone depleting substances’ are the nasty CFCs that the Montreal protocol has apparently got rid of completely. The ‘hole’, however, that is to say, the area of the thin ozone layer, seems to be much as it has been for the pst twenty years or more. Perhaps twenty years is too short a period about which to be decisive, but you might argue that the relationship between the nasty CFCs and the area of thinned ozone does not so far  seem to be a very important one. And I have somewhat the same feeling about the relationship of CO2 and temperature.

I am puzzled, once again, by the sudden rise in the area of thinned ozone from 1980. What evidence do we have of its size before that time? There is one reference I can find (in the article by the British scientists), and that suggests that there is an annual fluctuation in the amount of ozone in the stratosphere that was pretty similar from 1957 to 1980. Yes, it was declining over time, too. But what seems to be the case is that new instrumentation from the early 1980s has provided data that are not, at least to my eye, strictly comparable with the earlier data. In short, we don’t know, and no one says we do.

The comments below the WUWT article are really worth reading, and you will get some interesting suggestions about the whole issue, ideas that are not to be found in the Wikipedia article. For example, and I should have thought of this myself, who defines what ‘thinning’ or a ‘hole’ is? The answer is that it is quite arbitrary, and in part a function of how you define things (rather like ‘climate’ being the average of 30 years of ‘weather’, a definition based on convention).

Or perhaps Antarctica never had much of an ozone layer anyway (argued on the basis of physics, and sensible given my limited knowledge). Or that it is natural factors, not CFC’s, that determine the annual cycle. Or that it is concentrations, rather than actual emissions, that are important — which might explain the second diagram in this essay.

All in all, my old feeling that the Montreal Protocol was a good thing and has had a good outcome, is somewhat shaken.  Observations don’t seem to support the whole argument very well. Maybe they will in another fifty years, which is what NASA says, on the basis of models, but I won’t be around then.

Join the discussion 11 Comments

  • Don Aitkin says:

    A correspondent suggests to me that ‘The so-called hole in the ozone layer was a well-recognised phenomenon well before fluorocarbons were invented. It affected radio transmissions that were directed around the polar regions and there were monthly charts published to guide radio amateurs transmission (antenna) directions.’

    I’m following up this clue as best I can.

    • Don Aitkin says:

      And a footnote: WUWT reports that NASA claims that this very large ‘hole’ is the result of unusual cold in Antarctica. It expects the hole to disappear by 2070. A scientist says that all this is ‘consistent’ with what they know of the hole, ozone and the stratosphere. I guess it is, though I doubt that unusual cold in Antarctica is entirely consistent with the notion that the planet is warming (yes, I know it’s weather etc). See

      • dlb says:

        The current theory is that as CO2 increases, the lower atmosphere will warm while the stratosphere will cool. So I suppose NASA are referring to the Antarctic stratosphere where ozone breaks down and not the lower atmosphere.
        If you look at UAH satellite data for August – September 2015 in the Sth hemisphere, it has been cooler than normal in the stratosphere. This cooling has been largely offset by warming in the Nth hemisphere.
        The satellites have shown that the stratosphere has cooled since they started measuring in 1979. Looking at the graph below one gets the impression that the cooling has more to do with the 1982 El Chinon and 1991 Pinatubo volcanic eruptions, rather than increasing CO2. See the green plot in the graph below.

  • Bryan Roberts says:

    David Karoly (Uni Melb) repeated on ABC radio today that the increased size of the hole in the ozone layer was ‘perfectly compatible’ with climate change, and assured us that it would be gone by 2070.

    Maybe, so will climate change. I think it’s amazing how authoritative these guys can be about events that will (might) occur tens of years after they are dead.

  • Mark Hayes says:

    Many years ago I attended a lecture by the late John Daly. In passing he talked about how the thinning of the ozone over the South Pole had been recognised back in the mid 1950s. At the time they noticed that the ‘hole’ seemed to be getting smaller each year (you can sort of see that in the graphs in the paper from Farmen that you linked). His point was that they thought it as merely curious and something to be watched. These were the days before scientists had learned to parlay scientific ambiguity into a scare and finally into a career.

    From the very outset, there were those who doubted the CFC link. However, there was no constituency who were sufficiently disadvantaged by the proposed bans to fight them – well apart from the general public who would be required to pay more the the same product. But as always, the general public’s interests didn’t get a look in.

    So we have a ban which initially seemed to be working. But now the apparent repair is stalling. At the very least that provides support to those who see the thinning as a natural cyclic phenomena. As I recall, at the time of the ban, we were assured that the start of the repair would be obvious quite soon after 1996 when the developed world would cease all use of CFCs. Recall that there was concern in the NH countries about their athletes being fried at the Sydney Olympics. At the time they were assured that things would be on the repair by then. Now that things aren’t working out as planned we’re told that they always knew it’d take the better part of 50 years to resolve. (I have a theory that scientists calculate the length of time required to check their hypothesis based on the following formula : y = r+ n where y is the number of years we have to wait to see if they are right, r is the number of years left to retirement, n is a random value to give breathing space).

    So would a Paris agreement be like the Montreal Protocol? Given the caveat that I doubt there will be a PAris agreement worth the name, if it did happen it would be very much like Montreal – hailed as victory for science, completely against the interests of the general public, and probably completely useless.

    • dlb says:

      Yes, I seem to remember hearing that ozone “hole” should start to repair after the Montreal Protocol took affect. Whether this was written up in the literature or was just wishful speculation I don’t know?

      The current excuse seems to be that the ozone depleting chemicals have only decreased by 10% due to their longevity in the environment.

      It will be interesting to see what happens in years to come if the hole doesn’t budge. Expect some creative explanations involving CO2 🙂

  • Frank Brus says:

    Dr Sallie Baliunas has spoken against the CFC-Ozone scare a number of times. I would be interested in comments on her claims that the scare was unfounded and a forerunner to the AGW scam.

  • G van Rijswijk says:

    The original cc experiment by Rowland and Molina has been falsified. It is becoming increasingly obvious that the ozone hole fluctuates in line with the local climate – note NOT with ‘climate change’.

  • […] ban on CFCs the ‘ozone hole is recovering’ then, more strongly, ‘repaired’. But of course it isn’t. We have no real idea about the size of the hole (‘thinning of the layer’ is probably a […]

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