Because of the prevalence of fossil energy, the amount of CO2 shows an up-going trend, which can be regarded as the root cause of the rising temperature. As the driven force behind industrialization, fossil fuels, including coal, oil and natural gas are widely used in all aspects of people’s lives and productions. When fuels are burning, CO2 contained in them is emitted to atmosphere. For example, most of household equipment such as gas cooker air-condition and fridge consumes fossil fuels in a direct or indirect way, for the majority of electricity is generated by them. In the same time, Freon added to air-condition and fridge release waste CO2.Since the cost of exploring and operating clear alternative sources is high, traditional power energy can not be replaced immediately. Consequently, the control of greenhouse gas emission will take a long period of time.
In addition to consumption of fossil fuels, inappropriate agricultural practices also exacerbate climate condition. These practices can be divided into two parts, one of which is abuse of chemical fertilizers and another one is overgrazing. Specifically, if chemical fertilizers are overused, the original fertility of soil will decrease, releasing large amount of greenhouse gas. If grass lands are exposed to intensive grazing without sufficient recovery, their usefulness and productivity would be reduced. Even worse, overgrazing causes land desertification and erosion and temperature will increase faster without plants.
As for the effects of global warming, warmer temperature is the most fundamental and direct one. Evidences showed that the amount of CO2 in the atmosphere will double compared with that during preindustrial period and the temperature is predicted to rise by 1.8 degrees Celsius to 4 degrees Celsius. (Seitz and Hite, 2012,Global Issue,) However, it is only a part of the tragedy because