Discuss the causes of Global Warming

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Discuss the causes of Global Warming

    Ideally, the earth is constantly kept at an ideal temperature to sustain life of around 16°C (60°F).  The earth is heated by the sun’s rays in the form of visible short-wave light, the majority of these rays pass from the sun, virtually unstopped through the thermal ‘blanket’ of the earth’s atmosphere, and heat the surface of the earth.  This energy, after the earth has absorbed it, is transferred back into space as long-wave infrared energy.  The ‘natural greenhouse effect’ is the accepted warming up of the earth that is explained by the presence of naturally occurring greenhouse gases, and has been observed on other planets (Houghton, J 1994).  Global warming, however, has been and continues to be a major concern for the planet.  It is the process by which the earth’s surface is gradually increasing in temperature because of a variety of factors but primarily because of human activity, either by creating new sources of greenhouse gases or by obstructing natural sinks that eliminate them.

        Global warming is generally considered to be to be occurring because as this energy is radiated back into space the increased thermal blanket of greenhouse gases traps it and temperatures increase globally.  This thermal blanket is composed of water vapour, carbon dioxide, methane, nitrous oxide and ozone (United Nations Framework Convention on Climate Change (UNFCCC), 2001).  It is also referred to as the ‘greenhouse effect’ as the thermal blanket acts as a form of greenhouse for the earth that absorbs radiation and is able to retain it as fig. 1 illustrates (Houghton, J 1994)

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   There are three main factors contributing to global warming or ‘the enhanced greenhouse effect’ (Kemp, D 1994).  Firstly Carbon dioxide (CO2) accounts for over 60% of global warming.  It is estimated that every year 7000 million tonnes of carbon is released into the atmosphere every year (Kemp, D 1994).  It is stored in fossil fuels, such as coal and oil and released when they are burnt accounting for over 5 billion tonnes of CO2 emitted into the atmosphere every year (Keepin et al. 1986),  it is also stored in trees and released with the burning after deforestation.  This is ...

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