The oxygen that the humans breathe in is its molecular form O2 that consists of two oxygen atoms. Ozone, an allotrope of oxygen and a bluish gas, is formed by three atoms of oxygen. When found on the surface of the planet, ozone is considered a dangerous pollutant and is one substance responsible for producing the greenhouse effect. However, the ozone layer protects the Earth from the ultraviolet rays sent down by the sun. If the ozone layer is depleted by human action, the effects on the planet could be catastrophic. Ozone is present in the stratosphere which reaches 30 miles above the Earth, and at the very top it contains about 90% of all ozone. The sun’s some harmful rays are absorbed by the ozone in the stratosphere and thus do not reach the Earth.
In recent past, the ozone layer has been the subject of much discussion and rightly so, because the ozone layer that protects both plant and animal life on the planet is under threat. The fact that the ozone layer was being depleted was discovered in the mid-1980s. The main cause of this is the release of CFCs, chlorofluorocarbons. Antarctica was an early victim of ozone destruction. A massive hole in the ozone layer right above Antarctica threatens not only that continent, but many others that could be the victims of Antarctica's melting icecaps. Not in the distant future but right now, the ozone problem will have to be solved for ever so that the protective layer can be conserved.
Only a few factors combine to create the problem of ozone layer depletion. The production and emission of CFCs, chlorofluorocarbons, is by far the leading cause. While most of the countries have called for the end of CFC production, only a few produce the chemical. However, those of the countries where industries do use CFCs do not want to discontinue usage of this highly objectionable but equally valuable industrial chemical. CFCs are used in industry in a variety of ways because they are amazingly useful in many products.
Discovered in the 1930s by American chemist Thomas Midgley, CFCs came to be used in refrigerators, home insulation, plastic foam, and throwaway food containers. Only later did people realize the disaster CFCs caused in the stratosphere where, the chlorine atom is removed from the CFC as a free radical and attracts one of the three oxygen atoms in the ozone molecule. The process continues, and a single chlorine atom can destroy over 100,000 molecules of ozone as it works as a catalyst. In 1974, Sherwood Rowland and Mario Molina followed the path of CFCs. Their research proved that 99% of all CFC molecules, entering the atmosphere, would end up in the stratosphere. Only in 1984, when the ozone layer hole was discovered over Antarctica, was the proof truly conclusive. At that point, it was hard to question the destructive capabilities of CFCs and immediate need to ban their use. But even if CFCs were banned, problems would remain as there would still be no way to remove the CFCs that have been discharged and are now present in the environment. Nevertheless, clearly though, something must be done to limit this international disastrous problem henceforth.
Even minor problems of ozone depletion can have major effects as when even a small amount of the ozone layer is lost, more ultraviolet light from the sun can reach the Earth. Every time 1% of the ozone layer is depleted, 2% more UV-B is able to reach the surface of our planet. UV-B increase is one of the most harmful consequences of ozone depletion because it can cause skin cancer. The increased cancer levels caused by exposure to this ultraviolet light could be enormous. It has been estimated by the U.S. environmentalists that 60 million Americans born by the year 2075 will get skin cancer because of ozone depletion and about one million of these people can be saved from the sufferings of cancer by the ultimate remedy, the death. Some research shows that in addition to cancer, a decreased ozone layer will increase rates of malaria and other infectious diseases too. Further about 17 million more cases of cataracts can also be expected.
Above all the environment will also be negatively affected by ozone depletion. The life cycles of plants will change, disrupting the food chain. Effects on animals will also be severe, and are very difficult to foresee. Oceans will be hit hard as well. The most basic microscopic organisms such as plankton may not be able to survive. If that happened, it would mean that all of the other animals that are above plankton in the food chain would also die out. Other ecosystems such as forests and deserts will also be harmed. The planet's climate could also be affected by depletion of the ozone layer. Wind patterns could change, resulting in climatic changes throughout the world. Although the discovery of the ozone depletion problem came as a great surprise but it has been felt by all that now, action must be taken to ensure that the ozone layer is not destroyed. Because CFCs are so widespread and used in such a great variety of products, limiting their use is hard. Also, since many products already contain components that use CFCs, it would be difficult if not impossible to eliminate those CFCs already in existence. The CFC problem may be hard to solve at once because there are already great quantities of CFCs in the environment.
CFCs would remain in the stratosphere for another 100 years even if none were ever produced again. Despite the difficulties, international action has been taken to limit CFCs. In the Montreal Protocol, 30 nations worldwide agreed to reduce usage of CFCs and encouraged other countries to do so as well. However, many environmentalists felt the treaty did "too little, and too late. The treaty asked for CFC makers to only eliminate half of their CFC production, making some people feel it was inadequate. By the year 2000, the US and twelve nations in Europe have agreed to ban all use and production of CFCs. This will be highly significant, because these countries produce three quarters of the CFCs in the world. Many other countries have signed treaties and written laws restricting the use of CFCs. Companies are finding substitutes for CFCs, and people in general are becoming more aware of the dangers of ozone depletion.
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