The ozone layer diminishes more each year. As the area of polar ozone depletion (commonly called the ozone hole) gets larger, additional ultraviolet rays are allowed to pass through.
These rays cause cancer, cataracts, and lowered immunity to diseases.1 What causes the depletion of the ozone layer?
In 1970, Crutzen first showed that nitrogen oxides produced by decaying nitrous oxide from soil-borne microbes react catalytically with ozone hastening its depletion. His findings started research on "global biogeochemical cycles" as well as the effects of supersonic transport aircraft that release nitrogen oxide into the stratosphere.2
In 1974, Molina and Rowland found that human-made chlorofluorocarbons used for making foam, cleaning fluids, refrigerants, and repellents transform into ozone-depleting agents.3 Chlorofluorocarbons stay in the atmosphere for several decades due to their long tropospheric lifetimes. These compounds are carried into the stratosphere where they undergo hundreds of catalytic cycles with ozone.4 They are broken down into chlorine atoms by ultraviolet radiation.5 Chlorine acts as the catalyst for breaking down atomic oxygen and molecular ozone into two molecules of molecular oxygen. The basic set of reactions that involve this process are:
Cl + O3 -->ClO + O2 and
ClO + O -->Cl + O2
The net result:
O3 + O -->2O2
Chlorine is initially removed in the first equation by the reaction with ozone to form chlorine monoxide. Then it is regenerated through the reaction with monatomic oxygen in the second equation. The net result of the two reactions is the depletion of ozone and atomic oxygen.6
Chlorofluorocarbons (CFCs), halons, and methyl bromide are a few of the ozone depletion substances (ODS) that break down ozone under intense ultraviolet light. The bromine and fluorine in these chemicals act as catalysts, reforming ozone (O3) molecules and monatomic oxygen into molecular oxygen (O2).
In volcanic eruptions, the sulfate aerosols released are a natural cause of ozone depletion. The hydrolysis of N2O5 on sulfate aerosols, coupled with the reaction with chlorine in HCl,
ClO, ClONO2 and bromine compounds, causes the breakdown of ozone.
The sulfate aerosols cause chemical reactions in addition to chlorine and bromine reactions on stratospheric clouds that destroy the ozone.8
Some ozone depletion is due to volcanic eruptions. Analysis of the El Chichon volcanic eruption in 1983 found ozone destruction in areas of higher aerosol concentration (Hofmann and
Solomon, "Ozone Destruction through Heterogeneous Chemistry
Following the Eruption of El Chichon"). They deduced that the
"aerosol particles act as a base for multiphase reactions leading
While doing his research Molina learned that these compounds move up to the ozone and stay there. He expected the compounds to be destroy by the solar radiation. However to his surprise he formed that chlorofluorocarbons would simplify into component element when exposed to radiation. This simplify components produce a highly concentration of pure chlorine atoms. From there he already knew that the ozone layer can be destroy with chlorine.
As the twenty-first century progresses, it has become increasingly apparent just how many challenges the world faces. Prominent among these concerns are environmental issues, in particular, ozone depletion and climate change. While the international community has been exceptionally successful in its struggle to reduce the production and consumption of chlorofluorocarbons (CFCs), the organic compounds that contribute to the ozone issue, its efforts to tackle climate change have yielded considerably fewer advancements. A number of factors that helped the proceedings of the ozone regime, or campaign, are not applicable to the climate change regime. The issue of limiting CFCs was much less politically and economically charged than that of reducing greenhouse gases (GHGs), which cause the greenhouse effect and the consequent warming of the planet. Climate change has been referred to as the ultimate “tragedy of the commons”, an important metaphor in economics that helps explain why this subject is still at the centre of much heated debate and has yet to be resolved in a manner similar to that of the ozone problem.
The sulfur in volcanoes will turn into a gas. When sulfur comes into contact with the cold air it turns back into a solid. Sulfur has four isotopes which are sulfur-33, sulfur-34, sulfur-35, and sulfur-36. Sulfur-35 is a radioactive isotope, it is used commercially to make rubber and gunpowder. It is an essential and a vital nutrient for crops, animals, and people. It is in breast milk and can also be used as a fertilizer. Sulfur is in our food and we are exposed to it in our diet. Sulfur is also in some proteins and vitamins. Some people have even sprinkled sulfur in their yards to get rid of snakes, but it should not be used if you have pets or
Stratospheric ozone absorbs 97-99% of ultraviolet radiation. As this protective layer continues to dissentigrate, human health will suffer. One American dies every hour from skin cancer, a direct result of ozone depletion by anthropogenic chemicals, primarily CFCs, which damage the ozone layer. Alternate chemicals are now being used in the place of CFCs that will not damage statospheric ozone, and there is international recognition of the importance of developing these chemicals. The Montreal Protocol is an international treaty which limits the production of ozone depleting substances. Still, human health is at risk from the deletion of ozone, and the risk factor will continue to rise unless people and industries become more aware of the implications connected with everyday use of chemicals which destroy stratospheric ozone.
From the day-to-day use of CFC’s (Chloro fluoro carbons) and other depletion substances the ozone wears off more and more. These substances are referred to as ozone-depleting substances (ODS). They are usually found in chemicals and as a result of causing depletion in the ozone layer, cause skin cancer and disorder in humans and animals as well. CFC’s are used as coolers in refrigerators, and air conditioners. They used to be used in car air conditioners until 1995, when it was discovered the CFS’s were depleting the ozone. Industrially, they are found in solvents and sometimes in dry cleaning agents. Furthermore, cleaning agents, foam insulation and packaging materials are also known to aid in the ozone depletion.
* Nitrogen Oxides are presented through the atmosphere. N2O are very powerful in the chemistry of the troposphere and the stratosphere, and they are very important in ozone production and in the destruction processes. There are a number of sources (the oxidation of N2O like lightning and fossil fuel combustion) whose contribution to NOx concentrations in the upper troposphere is not well measured.
Cause: Disturbances in the Chapman Cycle (reactions that represents the natural formation and destruction of the stratospheric ozone [11]) by the CFCs (e.g. applications in air conditioning, automobiles, refrigerants, fire-extinguishers, etc.), nitrogen oxides (NOx) and other anthropogenic ozone-depleting substances. [12] For instance, UV radiation brakes bonds of CFC molecules, thus releases Cl atom, which in turn separates an oxygen atom from ozone molecule.
Thus CFCs became used all over the world and its business got bigger and bigger until late in 1973. Sherwood Rowland and Mario Molina, two distinguished chemists, came up with a surprising result in his calculations concerning the CFCs and ozone layer. CFCs are basically inactive in the troposphere(around the altitude of 50,000 feet) so it would gradually drift upward until they reached the mid-stratosphere.(about 100,000 feet) At this point CFCs would be broken down by short-wavelength ultraviolet radiation from the sun. This radiation is the one which would not reach the lower atmosphere in large amounts because of the ozone layer. When these CFCs do brake down, they released atomic chlorine which then would react with the ozone and convert it back into plain oxygen. The even worse part of all this is that these chlorine molecules do not become inactive after the first reaction with the ozone and would be available to destroy more ozone molecules. Thus this process would be the function of a catalyst; a single chlorine atom involved in a chain reaction to destroy many ozone molecules.
The United States releases twenty tons of carbon monoxide per person per year. Carbon Monoxide release is a result of burning fossil fuels with an insufficient amount of oxygen that causes the formation of carbon monoxide that pollutes our environment. Everyday fuel is burnt by cars, airplanes, large factories and manufacturing plants. This is causing a very large and deadly problem for our environment. When gases used on earth are released into the atmosphere they act as a blanket and trap radiation that is then redirected to earth. This concept is called the Greenhouse Effect (Bad Greenhouse, 1).
Throughout the years, advances in technology and scientific development have greatly influenced our global community. Various anthropogenic factors, such as the increased combustion of fossil fuels and widespread usage of manmade chemicals, have greatly affected the planet's atmosphere and it's ozone layer.
AQA GCSE Higher Sulphur dioxide (SO2) is a colourless gas, belonging to the family of gases called sulphur oxides (SO_). It reacts on the surface of a variety of airborne solid molecules, is soluble in water and can be. oxidised within airborne water droplets. http://www.doc.mmu.ac.uk/aric/eae/Acid_Rain/Older/Sulphur_Dioxide.html. Many factors can affect the rate of reaction; concentration. temperature, ratio of the substances, amount, stirring, and catalysts. are these factors.
Chlorofluorocarbons [CFCs], commonly known as Freon, are a type of organic compounds that are made up of carbon, chlorine, and fluorine atoms. Their significant properties include low volatility of approximately 0℃, together with being tasteless, odourless, non-flammable, nontoxic, and chemically stable. They have supported the society for years through the form of a refrigerant, a solvent and a propellant. Moreover, they have contributed to the industrialization of nations, especially during the 1950s, as a material to manufacture aerosol sprays, and as a blowing agent for foam and packing materials. Ironically, in addition to being a useful compound in many instances, it was found that CFCs have been a leading cause of global warming and the annihilation of species. In 1985, Joe Farman and colleagues discovered and named the destruction of the ozone layer as “the Antarctic ozone hole”. The ozone layer is part of the ozone rich stratosphere – a layer of the earth’s atmosphere that sits approximately 20m above the earth. The main function is to protect the earth from harmful ultraviolet rays [UV rays] emitted from the sun. Thus, the discovery of a hole in the ozone layer was a serious environmental issue. Through investigation, it was found that one of the major factors of the ozone layer deterioration was the production of CFCs. When CFCs reach the atmosphere, they react with UV rays, and turns into substance including chlorine. The chlorine takes place a chemical reaction with the oxygen in ozone, destroying the ozone molecules (See figure 1). According to the US Environmental Protection Agency, a single chlorine atom in the ozone layer can abolish 1,000 zone molecules. In the following essay, the effect of the CFCs on the ozone...
The United States Environmental Protection Agency set protective, health-based standards for ozone in the air. Throughout the United States, many programs have been initiated and aimed at reducing NOx and VOC emissions from motor vehicles and industrial and electrical facilities. Some programs have set goals to reduce pollution by encouraging communities to use cleaner alternatives such as carpooling to reduce dangerous pollutants (United States Environmental Protection Agency, 2014). While this has helped reduce “bad” ozone in the troposphere, there were still depletions in the stratospheric “good” ozone layer. Various combinations of chemical elements such as carbon, chlorine, fluorine, bromine, and hydrogen are typically characterized as halocarbons. As reported by the National Oceanic and Atmospheric Administration, “the compounds that contain only chlorine, fluorine, and carbon are called chlorofluorocarbons, usually abbreviated as CFCs,” (2008). CFCs, carbon tetrachloride, and methyl chloroform are ozone-depleting gases that have been produced by humans. These gases are commonly used in everyday life. For example, CFCs are found in air conditioning, foam blowing such as fire extinguishers, refrigeration, coolants, and in the cleaning of electronics components. Once these particles are released into the air, these substances degrade extremely slowly; some surviving for years as they reach
The ozone layer is situated in the stratospheric layer of the atmosphere. It is important to the on-going stability of life on Earth as it prevents harmful UV-B radiation from reaching the troposphere (i.e. the layer of atmosphere that we live in). Were this radiation to reach us in large quantities, it could mutate the DNA in our cells and have fatal results. It is thanks to the ozone layer that this doesn’t happen, but a hole has formed in the ozone layer over Antarctica which could affect us severely. The ozone hole is a great loss of ozone molecules in the stratosphere above Antarctica. During winter, wind vortexes form around Antarctica and temperatures drop to below -78oC which result in ice, nitric acid and sulphuric acid clouds. Reactions of chlorofluorocarbon molecules using these clouds as a reaction surface result in active forms of halogens from the chlorofluorocarbons being stored. The ozone hole forms as spring arrives along with warmer temperatures and the active halogens are released and act as catalysts to eliminate the ozone molecules. Ozone levels can drop to around 50% during this time. In the following months, the ozone hole is able to repair itself, but this is a slow process.i
The ozonosphere or as we know it, the ozone layer, is the region of the Earth’s upper atmosphere. It contains a high concentration of ozone molecules. The ozone molecules in the ozone layer work to block an estimated 97-99 percentage of solar radiation from reaching the Earth’s surface. If the ozone layer were not present the radiation from the sun would kill most living things and make our planet uninhabitable. The size and thickness of the ozone layer varies by location and the time of year. It is larger towards the poles of the earth and at its thickest during the spring time. The ozone layer was first discovered by Charles Fabry and Henri Buisson in 1913. In 1958 a network of ozone monitoring stations were established and still operate today. It is important to understand and monitor our ozone layer in order to protect ourselves from the sun’s harmful radiation. We will look at the current status of the ozone layer, the main causes of its degradation, and what the future holds for the ozone layer if we don’t change the way we live.