It was easy not to know. Pouen from the last climate crisis

At first glance, questions about climate change may seem to be a specific problem today. Even a glimpse into the past shows that humanity has had similar problems in the past. One in the past is so guilty that most of us remember her.

Climate change, the role of the hunter, the currency and the economic consequences are becoming the focus of the current public debate. We do not have enough unquestionable data, we do not perform experiments and we are based on numerical modeling. However, the cost, and its inaction, or discouraged activities, can be reversibly high.

In a similarly uncomfortable situation, however, we are not the first time. At the age of seven and eight, the depleting ozone layer of the Earth was discussed with similar vigor. Given the identity of historical analogies, it is important to recall the disputations of the time.

He had to repeat

Let’s repeat something about ozone. This reactive form of oxygen was discovered in 1838 by Christian Friedrich Schnbein during the electrolysis of water. The name of this bluish, tipping and toxic gas is also derived from the Greek assassination for the outside, and its unpleasant effects can be encountered on sunny summer days in the form of photochemical smog.

At the age of twelve, the study of the solar zen spectrum showed that ozone occurs in the stratosphere, and in the ten years the British meteorologist Sydney Chapmann elucidated the mechanism by which ozone is formed, ie by the formation of solar zen on white oxygen. And in a moment it was so clear that the first ozone carried and gave the organisms protection especially against the harmful mole-wave UV-B.

The proposed mechanism allows to model atmospheric concentrations using laboratory data on the rates of chemical reactions. Accurate data on chemical reactions began to appear in the fifties. It turned out that something did not fit quantitatively on Chapmann’s mechanism. Ozone was low compared to the models.

By adding further reactions, specifically between ozone and nitrogen oxides, the model was refined. At the same time, the idea that the ozone layer is a little shaky and human activity is slowly becoming more intrusive. The first concern was about nuclear tests that took place in the last six years. Thanks to their political role, these agreements ended despite their potential role in the ozone budget. Concerns followed of supersonic planes producing nitrogen oxides. Here again, the invisible hand of the market helped, the commercial operation of these aircraft did not fill up. Only then did the threat of freon appear.


Changes in total and Antarctic ozone. One Dobson unit (DU) expresses the amount of ozone that, at a pressure of 1013.25 hPa and a temperature of 0 C, would form a layer 10 micrometers thick. The decrease in Antarctic ozone concentrations is due to a decrease in global concentrations.

Prvn alarmist

In 1974, Mario Molina and Sherry Rowland wrote an alarmist article in the journal Nature, in which they pointed out the decomposition of ozone by chlorine radicals from chlorinated hydrocarbons (especially CF2Cl2 a CFCl3), produced by hunters and used in the refrigeration industry, in sprays and as blowing agents.

They were based on the fresh names of James Lovelock (known mainly as the author of the Gaia hypothesis), who was able to detect even traces of CFCs. It turned out that in the atmosphere (more precisely in its lowest layer, in the troposphere) remained dark all freons until then. Freons are insoluble in water, insoluble by visible light and chemically unreactive.

Rowland and Molina asked themselves what would happen to these sticks in the end, and the kilns could not accumulate in the atmosphere indefinitely. They have come to the conclusion that these gases will gradually and very slowly rise from the troposphere to the stratosphere, where they will decompose with light and at the same time catalyze the decomposition of ozone. And that goes after ten years.

Their data showed that at 9% of the number of consumption observed in the United States in 19611971, the ozone layer would be 4 and 7 percent by 1995, and 30 and 50 percent by 2050 compared to the time before CFC production.

An important detail is the fact that in the middle of the seventeen years the ozone depletion layer was not observed. it was only a kinetic and diffusion model. Significantly depletion of ozone layers predicted and in the future. The description of the items themselves in a two-sided link takes only a few days. At the same time, the industry associated with CFCs in the United States alone posed a real threat to several hundred thousand people, a real threat of the immediate loss of labor, and thus counteracted the previous problems in the distant future.

In addition, the models used were subject to a number of inaccuracies. Sm Rowland, for example, showed in 1976 that a hitherto unprecedented compound derived from chlorine radicals ClONO2 the amount of ozone compared to the original assumptions of changes. The predictions differed from model to model. There is a kind of improvement of this kind in science, but in the meantime the discussion did not take place only on the pages of scientific journals.


The ozone over Antarctica in 2006, when it was the largest species in the djinch men.


The social reaction was surprisingly fast for one day. In 1975, a proposal for restrictions on the production of CFCs emerged from the American government, and in 1977 CFCs in aerosol sprays were banned in the United States.

Not surprisingly, he saw the reaction. Freon manufacturers have paid full-page ads advocating the use of freon and emphasizing that the prediction of ozone depletion is just a theory. Thus, suggestions have emerged that, in contrast to natural sources of chlorine, for example from volcanic activity, anthropogenic sources are insignificant.

The intensity of UV-B women in cities has been exacerbated by the presence of aerosols in the eighties, which has fueled ozone skeptics. Economic cost-benefit analyzes have highlighted the enormous costs and irreversible economic code that restrictions impose.

Jet in 1987, full personal protection appeared in the US administration (Personal Protection Plan), which he considered as an alternative to the destruction of chlorinated hydrocarbons adapted to the new situation. The discussion shifted from the scientific level to the ideological level. The critics of the panic over the grievances over grants, prestige and words did not remain criticized.

We recall again that driving at the age of eight was not a decisive observation of the decrease in ozone concentrations (see graph on the left), although the catalytic mechanism of ozone decomposition was confirmed by the reduction of reactive radicals in the stratosphere. Companies in Peru were already developing the development of CFCs and the crisis, which did not exist, seemed to be over. But then there was a dramatic twist.

Men in Antarctica in June 1985 showed a 30% decrease in ozone concentration and the so-called ozone dra has since been observed in cadorone. It turned out again that there were two ozone sources on satellite imagery, but data with extremely low ozone concentrations were reported as unreliable. Thus, the authors of the first study on the depletion of the ozone layer in Antarctica have been going on for a long time, but the results did not make sense to them, they also carried out a new name, but they did not decide to publish the data.


Brewerv spectrophotometer that monitors the total amount of ozone in the atmosphere and sunny UV women in the Antarctic region.

Kinetic models working with gas phase reactions could not explain the ozone species. Chlorine radicals play a dominant role here, as it was formed by chemical reactions on ice floes. But it wasn’t clear from the meeting. An alternative hypothesis was e.g. the current air mass with low ozone content into the Antarctic stratosphere would not help the destruction of freon.

Despite the lack of consensus on the dry ozone pin, the Montreal Protocol was adopted in 1987, which massively reduced the production of chlorinated hydrocarbons. All the then 197 only UN was added. The Montreal Protocol was set to a regular reassessment regime and was followed by more stringent ones. Unlike the opponents of the devastation, the freon replacement turned out to be a fully functional unit. However, global ozone concentrations have been steadily declining in the 1990s and are beginning to stabilize and even increase slightly over the new millennium.

The ozone crisis has gone through a familiar cycle: the phenomenon does not exist, the phenomenon is not caused by the hunter, and not by the way of more code than good. The community of atmospheric chemists, physicists and meteorologists came to a consensus fairly quickly, with counter-arguments coming from experts in other fields. The Montreal Protocol violated the presumption of innocence as a retrospective phenomenon. However, the industry has also played an important role in the fact that the alternative route is easier and I am interested in flattering.

The text was taken from the magazine Vesmr, and before publication it was edited. You can find the original here. lnek pat do srie text on the darkness of the climate, which were published in the summer double of the magazine Vesmr.

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