Our Changing Atmosphere

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The purpose of this essay is to consider the current environmental issues of an enhanced greenhouse effect and global warming with particular reference to the changes that are taking place in response to Greenhouse Gases interacting with the atmosphere and the effects these changes are having on naturally occurring reactions and processes that impact on our planet and our way of life. The aim of the essay is to examine the evidence available to support and refute current claims of imminent threats to life on our planet and a need to actively respond now. Global Warming is an imminent occurrence that society faces on a daily basis; the effects of an increasing number of fossil fuels means that there is an increasing amount of CO2 being emitted compared to O2 which is slowly affecting the air not only humans but plants and animals breath on Earth. The greenhouse effect is a natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. These greenhouse gases are polluting the Earth’s atmosphere and are one of the many reasons why the Earth has an increasing surface temperature.

Carbon Dioxide or C02 is a by-product of the combustion or burning of fossil fuels such as coal and oil, it is present at the highest concentration out of the Greenhouse Gases in our atmosphere (Kreger C, November 2004). Based on 1990 concentrations, carbon dioxide is said to be responsible for almost 60% of the total greenhouse effect. Its concentration is increasing in the atmosphere due in large part to the extensive burning of coal and other fossil fuels for energy production (EPA, 2014). The Chemical process of combustion can be showed by 6 O2 + C6H12O6 --------> 6 H2O + 6 CO2 + energy (Kreger C, November 2004). Methane or CH4 is present in the atmosphere at less than 1% the levels of carbon dioxide, however it is 25 times more efficient as a greenhouse gas. It contributes to a little over 10% of the total greenhouse effect based on current concentrations. The primary cause of Methane emissions are the combustion of fossil fuels, and the decomposition of organic materials associated with wetlands, rice paddies, and livestock manure (EPA, April 2014). Methanogenesis or biomethanation is the formation of methane by microbes known as methanogens. Methanogenesis in microbes is a form of anaerobic respiration. Methanogens do not use oxygen to respire; in fact, oxygen inhibits the growth of methanogens. The terminal electron acceptor in methanogenesis is not oxygen, but carbon. The carbon can occur in a small number of organic compounds, all with low molecular weights. The two best described pathways involve the use of carbon dioxide and acetic acid as terminal electron acceptors (Thauer, R. K., "Biochemistry of Methanogenesis: a Tribute to Marjory Stephenson", Microbiology, 1998, volume 144, pages 2377-2406): During the microbial metabolic process of methanogenesis, acetate (CH3COOH) is split into CO2 and CH4 (Kreger C, November 2004): Which can be showed by CH3COOH --------> CO2 + CH4. Nitrous oxide or N2O also occurs in low concentrations relative to carbon dioxide, but it is 230 times more efficient as a greenhouse gas. These factors combine to make it a 6% contributor to total the greenhouse effect. The primary anthropogenic sources are fossil fuel combustion, fertilizers, and deforestation (EPA, April 2014). Per/Chlorofluorocarbons are the only Greenhouse Gases that are not naturally occurring and are a main contributor to the atmospheres Greenhouse Gases problem. They come solely from anthropogenic sources such as the production and/or use of foams, aerosols, refrigerants, and solvents. They are present at an extremely low concentration in the atmosphere; however they are 15,000 times more efficient as a greenhouse gas relative to carbon dioxide. As a result, they contribute to approximately 25% of the...
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