Global warming: The burning of fossil fuels, (coal, gas, petroleum), the cultivation of the soil, large scale industrialisation, rapid means of transport and deforestation has caused an imbalance in the atmosphere. These activities are increasing the amount of carbon dioxide. Thus, the greenhouse effect has raised the average, the temperature of the earth by 0.5°C. By the year 2000, the earth’s, average temperature will go up by 2°C. This is called global warming. Global warming is causing a rise in sea-levels due to the melting of glaciers. It is threatening to submerge many coastal areas.