The problem of ozone depletion is so loud that it has come across your ears more than once or twice. Perhaps you have heard about it in the media or even at school. From the 1980s, scientists began a crusade against freons that could completely ruin our ecosystem. What causes such complications? What should we be afraid of? Finally – is the ozone hole still threatening us?
Ozone depletion is a phenomenon that reduces the amount of ozone in the stratosphere (more precisely, in the ozonosphere). This is a very dangerous process because the ozone layer protects us from ultraviolet radiation by absorbing a large part of the rays that reach the Earth from the sun.
Ozone is formed and decomposed under the influence of sunlight, therefore its fluctuations over the year are noted.; Iin addition, the natural state of the ozonosphere varies with latitude. Nevertheless, scientists noticed a marked decrease in the ozone content in the stratosphere in the 1980s and proved that this is an anthropogenic loss. This means that people are to blame for this state of affairs, and more specifically the increased emission of freons used in the production of aerosols. The largest “holes” in the ozonosphere are observed in the polar regions, especially over Antarctica.
Stratospheric ozone is produced by the action of UV rays on oxygen molecules. At the same time, the sun’s rays affect the freons that enter the atmosphere and break them down into chlorine, carbon and fluorine. Ozone reacts with the chlorine atoms and breaks down into ordinary diatomic oxygen. These reactions continue until the chlorine is completely removed or … the ozone particles are depleted.
Unfortunately, the freon particles do not break down in the troposphere and do not react with other substances; they can circulate in the atmosphere for up to 100 years without any damage. They only decompose when they enter the ozonosphere. It was calculated that the ozone content decreased at an alarming pace – at the equator by about 0.2% per year, and in moderate latitudes to 0.8% per year. The worst, however, was just over Antarctica, where the loss widened at a critical moment by as much as 15%.
Why are the polar regions particularly vulnerable? Unfortunately, gases, including CFCs, travel throughout the atmosphere and reach the poles as well. Even though Antarctica is very far from the largest emission sources, Europe and the United States, it still reaps a toll on mistakes made in highly developed countries. The problem is made even more difficult by the polar night – due to the long period of underexposure, ozone is produced much slower, while its decomposition caused by pollution does not stop at all. Ozone is destroyed faster than produced, and this heralds a systematic reduction of the ozone layer and … an ecological catastrophe.
Why is the ozone hole such a pressing problem? It turns out that it can have very serious consequences for life as we know it. The main task of stratospheric ozone is to absorb UV rays, which can be very harmful to living organisms. They can lead to skin burns and cell damage, permanently change the genetic material and cause cancer, including melanoma. In addition, UV radiation causes a decrease in immunity and makes the body more susceptible to infection with viruses or parasites. Unstoppable sun by ozone can worsen the condition of the skin (if we do not use sunscreen, we risk accelerated aging processes); it is also very dangerous for the eyes and can cause cataracts (which is why wearing sunglasses is so important).
The ozone hole is dangerous not only for humans and animals, but also for the whole Earth – including plants and the environment. UV radiation harms many species of food plants and reducing the amount of ozone in the atmosphere causes significant climate change.
Even 25 years ago, freons were used on a widespread scale, incl. in varnishes, the cosmetics industry and medicine, as well as in compressors, air conditioning and refrigeration devices.
In 1985, shortly after the shocking discoveries of scientists, the so-called Vienna Convention on the Protection of the Ozone Layer. It obliged the signed countries to reduce freon emissions and to conduct known measurements. Two years later, representatives of 20 countries also signed the elaborate Montreal Protocol, which obligated the complete abandonment of freons. To date, 160 countries have agreed to its terms, and CFC emissions have fallen by over 90%.
In 2018, we could read very good news in Deutsche Welle – the protective ozone layer has finally started to rebuild. Since 2000, treatment has been maintained at a rate of around 2% per year. At the same time, the resumption of freon-11 emissions in the area of East Asia was detected, and the UN called for the exact identification of the source.
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