Since the early 1970s scientists have been debating heatedly about the causes and consequences of global climate change. To date, there seems to be a strong consensus among scientists about continuing and remarkable changes in the global climate over the past 150 years. According to the Intergovernmental Panel on Climate Change (IPCC 2007), the global average surface temperature has increased by almost 1°C in the past 100 years. In general, climatologists and other experts agree that this global warming is partially attributable to the combustion of fossil fuels by humans. Other physical evidence pointing in the direction of global climate change is the global average sea level, which rose by approximately 17 cm during the 20th century. Thermal expansion of sea water and loss of land ice are the main causes of this effect. The IPCC (2007) further predicts that global warming will continue owing to ever-increasing human energy consumption and economic growth. Global average surface temperature will increase by another 2° to 4°C, and the sea level is projected to rise by another 20 to 60 cm during the 21st century.