Global warming has becoming an increasingly important issue in our environmentally conscious society as it is a problem affecting every aspect of the environment and the living beings everywhere on this planet. Yet, it is quite controversial as to its nature, cause, and the effects it will bring along in the future.
The average temperature of the earth’s surface has risen by 0.8 degree Celsius since 1880. The International Panel on Climate Change (the IPCC), based on the work of hundreds of scientists in more than 100 countries, has concluded in its 2007 report that this current planetary warming is mainly caused by human activities, such as the burning of fossil fuels, deforestation, and agriculture. (The IPCC 2007 Synthesis Report)
These activities have greatly increased atmospheric concentration of greenhouse gases, especially carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). These greenhouse gases are naturally occurred and essential for life on earth as they trap the sun’s heat and keep the earth warm. If these gases were removed from the atmosphere, the earth’s temperature would plummet to -18 Celsius, far too cold to sustain our current ecosystem. However, humans are causing massive increase in these greenhouse gas emissions, enhancing their heat- trapping ability. As a result, the temperature is rising higher and higher. (Pidwimy, 2006)
Scientists have also found that CO2 is the most important greenhouse gas which is responsible for 55% of the current warming. The atmospheric concentration of CO2 increased from 280 parts per million (ppm) in 1750 to 379 ppm in 2005. The principal reason for this mounting CO2 levels is the use of fossil fuels and changes in land use: the burning of oil, gasoline, and coal for running cars, factories, and generating electricity, and the cutting down of forests to make way for farming, housing and other development. Emissions from fossil fuel combustion contribute about 65% of the