to the increase in temperature of the earth’s lower atmosphere and oceans in the twentieth and twenty-first centuries. In recent years scientists all over the world have noticed a steady and slight increase
in temperatures of 0.6 degrees since 1900. The Intergovernmental Panel on Climate Change indicates that observed increases in globally averaged temperatures since the mid-twentieth century is very likely due to man-made greenhouse gas concentrations. Scientists are predicting that if greenhouse causing gases are not reduced then average worldwide temperatures could increase by 5 C by 2100. Increases in global temperatures will cause sea levels to rise and there will be an increase in severe weather events such as droughts, floods and storms. This will dramatically affect agricultural yields, lead to glacier retreats, species extinction and increase the range of diseases such as malaria (Porteous, 2000).