Write a summary of the Following passage (Max 5-6 sentences ).

There are many causes of greenhouse effect. The deforestation and burning down of the tropical forests, rapid growth of unplanted  industry, overpopulation, increase of temperature etc. are the key factors of greenhouse effect. Over population is a problem for any country. They need additional things for their survival. They need to cut down trees to build their houses, furniture , boat, fuel etc. Thus we are losing our forests and trees. It causes of natural imbalance. The use of various chemicals in mills and factories has a great effect on our environment. Besides, these mills and factories emit black smoke and polluted the air . Thus deforestation, the rapid growth of unplanted industries, the use of chlorofluorocarbons in packing and manufacturing chemical produce etc. produce huge amount of carbon dioxide gas, which acts as the main agent of greenhouse effect.