ISSUES AND CONCERNS ABOUT THE OZONE LAYER DEPLETION
INTRODUCTION
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. In recent years, the ozone layer has been the subject of much discussion. And rightly so, because the ozone layer protects both plant and animal life on the planet. The atmosphere is divided into five layers: the troposphere, the stratosphere, the mesosphere, the thermosphere, and the exosphere. The troposphere is the layer closest to earth and is where all weather happenings occur. The stratosphere is located directly above the troposphere, about 10-50 kilometers above the planet, and houses
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Although natural phenomena can cause temporary ozone loss, chlorine and bromine released from man-made compounds such as CFCs are now accepted as the main cause of this depletion. The production and emission of CFCs, is by far the leading cause.
Human activity is by far the most prevalent and destructive source of ozone depletion, while threatening volcanic eruptions are less common. Human activity, such as the release of various compounds containing chlorine or bromine, accounts for approximately 75 to 85 percent of ozone damage. Perhaps the most evident and destructive molecule of this description is chloroflourocarbon (CFC). CFCs were first used to clean electronic circuit boards, and as time progressed, were used in aerosols and coolants, such as refrigerators and air conditioners. When CFCs from these products are released into the atmosphere, the destruction begins. As CFCs are emitted, the molecules float toward the ozone rich stratosphere. Then, when UV radiation contacts the CFC molecule, this causes one chlorine atom to liberate. This free chlorine then reacts with an ozone (O3) molecule to form chlorine monoxide (ClO) and a single oxygen molecule (O2). This threatening chlorine atom then continues the cycle and results in further destruction of the ozone layer. Measures have been taken to reduce the amount of CFC emission, but since CFCs have a life span of 20-100
However, the effect of this process was unknown. Within three months, the pair developed the CFC ozone depletion theory. They determined that as the CFCs are broken down by solar radiation, the chlorine atoms are released into the atmosphere. As the chlorine atoms encounter ozone molecules, the two react to form chlorine oxide and an oxygen molecule. When the chlorine oxide molecule encounters another ozone molecule, two oxygen molecules form, the chlorine molecule is released, and the process begins again. Molina determined that over 100,000 ozone molecules could be destroyed by a single chlorine atom. In addition, CFCs could contain up to four atoms of chlorine per molecule. Molina predicted that in 60 years, CFCs could destroy 7% of the ozone in the earth's
The ozone is a form of oxygen that combines three oxygen atoms in each molecule. Its important because its like a filter. CFCS, also known as, chlorofluorocarbons are used to break up some of the ozone molecules
The ozone should always stay in tact to protects the earth from UV radiation, which is harmful to humans (skin cancer) and also the earth (global warming). If allowed to build up indoors, VOCs often contribute to lightheadedness, headaches, allergies and more importantly has also scientifically proven harmful to asthma sufferers. As a matter of fact, according to Professor Roy Harrison, professor of environmental health at Birmingham University, there is a body of research on VOCs in the indoor environment which links them with those kinds of symptoms - headaches and not feeling so good (news.bbc.co.uk). After proven to have negative effects on the ozone layer as well as humans, the production of CFCs was shut down and in fact it’s banned in the US. Some scientists were not convinced by the act of banning CFCs in spite of all these evidences. “Given the large economic impact of a ban — it was estimated that industries relying on CFC production generated $8 billion in business and employed 200,000 people in 1974 — several scientists in the field advocated waiting a few years for science to make more progress on the issue before making any policy decisions.” (bio.sunyorange.edu)
In the late 1970’s scientists concluded that products releasing carbonflourochloride (CFC) was causing the ozone to deplete. The ozone layer is a protective layer from the sun’s rays and depleting the ozone layer allowed the stronger, harmful to health on earth, rays to get through. International action was taken in 1987 and the Montreal Protocol came into being. It was an international treaty to phase out CFC producing products. It went into effect in 1988 and has achieved international success. Once the Montreal Protocol had been agreed to the World Health Organization released information on the harmful effects CFC’s were having on the ozone
Did you know that with all this talk about global warming, and the disappearing of the ozone layer, the root of the problem is us? Yes, we’re the cause of all those problems. We keep putting something called greenhouse gases into the air. A few greenhouse gases are water vapor, carbon dioxide, and methane. While some climate change is natural, humans need to be careful about greenhouse gases because ecosystems are changing, sea levels are rising, and global average temperature increased by more than 1.3 degrees Fahrenheit over the last century.
How do CFCs or chlorofluorocarbons affect Canada’s Ozone layer. To answer this question we first have to understand chlorofluorocarbons and the earth's ozone layer. Chlorofluorocarbons are chemical compounds made up of three chlorine atoms. One fluorine atom and 1 carbon atom. There were many uses for CFCs ranging from, being used as coolants in refrigerants to propellants for aerosols to being used as solvents for dry cleaning. As CFCs are non- flammable and not very toxic we thought they were a revolutionary compound, but unfortunately CFCs were one of the leading causes for the depletion of our ozone layer. ozone is a type of oxygen, an ozone molecule consists of three oxygen atoms whereas a regular oxygen molecule only consists of two.
The ozone layer is in the Earth’s stratosphere and the necessity of this layer is to protect the Earth from the sun’s harmful ultraviolet radiation rays. “Since the late 1970s, an ozone hole has formed over Antarctica each austral spring (September / October), in which up to 66 percent of the total ozone is depleted” (Ozone Layer Protection). What directly causes holes in ozone are Chloroflourocarbons (CFCs), which rapidly damage the ozone layer. However, with the rising global warming temperature the CFCs’ process is catalysed, further damaging the ozone layer. “According to the estimates made by Dasgupta and Bhaumik (1995), it is likely that 10% decrease in ozone will lead to 20% increase in UV irradiance” (Gangul and Iyer 2006). Once an uncontrolled amount of UV radiation is exposed to lifeforms, especially to humans, “According to the estimates made by Vander Leun and De Gruijl (1993), 1% decrease in total stratospheric columnar ozone (SCO) will lead to 2.3% increase in non-melanoma skin cancer, 2% increase in cutaneous melanoma and 0.5% increase in the incidence of cataracts” (Gangul and Iyer 2006). More devastating effects from the depleting ozone layer are more destruction to agricultural fields, warming of oceans and increased acidity which is diminishing the amounts of phytoplankton, which can immensely affect the stability of the food chain. Therefore, the depletion of
In 1988, the National Aeronautics and Space Administration had conclusive proof products adding to the output of carbon dioxide and methane gases in the atmosphere were causing the earth to warm; and, if not stopped will make it inhabitable for human life. In the 1970’s the United States had conclusive proof that products releasing Chlorofluorocarbons into the atmosphere were causing the ozone layer to deplete; and, that if continued would be dangerous for human life. The United States took international global action, by joining the Montreal Protocol, to phase out the products producing chlorofluorocarbon and the ozone layer has been successfully replenished .
The most widespread pollutant in the U.S. is ozone which is also one of the most dangerous. The ozone layer found high in the stratosphere shields us from a lot of the sun’s UV rays. When Ozone pollution (or smog) is at ground level where we can breathe it, it causes serious health problems; it’s dangerous to breathe, it aggressively attacks lung tissue by reacting chemically with it, it may also cause premature birth, premature death, infant mortality, and neurodevelopmental disorders like autism.
Apparently, Ozone is a lung-searing gas, which brings irritations in the airways causing respiratory problems (Kim, et al. 137). In California, both ozone and particulate matters have increased the heart and respiratory diseases such as asthma, lung diseases, bronchitis and heart problems for both children and adults. Nevertheless, some of this other harmful gas such as Carbon(II) Oxide, Nitrogen(IV) Oxide, and Sulphur(IV) oxide has also brought about cardiovascular
My first reason is because of a chemical called chlorofluorocarbons (CFCs). It has a tendency to drift up to the layer of ozone gas that surrounds the Earth and break up the ozone molecules. CFCs were found in aerosol cans that sprayed substances like deodorant and hairspray and in refrigerants, fire extinguishers and solvents for cleaning. Other ozone depleting chemicals were found
The third gas is nitrous oxide. Nitrous oxide has pretty much the same effect on the ozone as the chloroflourocarbons, but nitrous oxide only destroys about one-forth of what the chloroflourocarbons destroy.
Why is the ozone layer of much concern to scientists and environmentalists? The ozone layer is quite beneficial to human life and existence. The destruction of this layer has been linked to the now common health conditions such as cancers, skin conditions and cataracts among others. It is apparent that, without the ozone layer, all humanity would be lost to disease.
National Geographic wrote the article “Good Ozone, Bad Ozone”. The article is about how there are both good parts of the ozone layer and some bad parts of the ozone layer. The ozone layer is only good when the gas is high above the ground if it is not then it can be very harmful for us. The bad thing about the ozone layer is it is made up of poisonous gasses. Approximately 90 percent of the earth’s ozone is called the stratosphere. Many scientists believe that ozone layer is being destroyed due to chemicals we use. The National Geographic was motivated to write this article to educate us on how the ozone layer has a good and a bad layer. Even though, the ozone layer is helpful because it protects us from harmful ultraviolet rays. It can be bad when the layer is depleted and
Chlorofluorocarbons (CFC’s): CFC’s are lowering the average concentration of ozone in the stratosphere. “Since 1978 the use of CFC’s in aerosol cans has been banned in the United States, Canada and most Scandinavian countries. Aerosols are still used around the world and accounts for 25% of global CFC’s use”. (Miller 448). Spray cans discarded or leaking refrigerator and air conditioning equipment and the burning plastic foam products release the CFC’s into the atmosphere. Depending on the type, CFC’s stay in the atmosphere from 22 to 111 years.” Chlorofluorocarbons move up to the stratosphere gradually over several decades. Under high energy ultra violet (UV) radiation break them down and release chlorine atoms, which speed up the breakdown of ozone (O3) into oxygen (O2). Chlorofluorocarbons, also known as Freons, are green house gas that contributes to global warming. Photochemical air pollution is commonly referred to as “smog”. Smog is the contraction of the words smoke and fog, smog has been caused by water condensing on smoke particles, usually from burning coal. With the introduction of petroleum to replace coal economies in countries, photochemical smog has become predominant in many cities, which are located in sunny warm and dry climates with many motor vehicles. The worst episodes of