. Assertion Deforestation is one main factor contributing to global warming.
Reason Besides CO2, two other gases methane and CFCs are also included under green house gases.
Solution: Carbon dioxide is a green house gas. It is exclusively confined to the troposphere. In a normal situation, the temperature of earth is maintained by the energy balance of the sun rays which strike the planet and the amount of heat from being re-radiated to the surface of earth to the external environment. If, somehow, an increase in CO2 concentration happens, then the thick layer of this CO2 gas prevents the heat from being re-radiated out. This CO2 layer, thus, functions like a glass panels of a green house. This allows the sun light to pass out through it but does not allows the heat from being re-radiated back into the outer space. The net effect of green-house effect is the heating up of the earth’s surface.
Removal of forests for the purpose of building construction and other similar purposes by humans, is called deforestation. That is a major factor contributing to global warming. CO2 contributes 57% part in green house effect besides it CFCs 15%, methane 12%, nitrogen oxides 6% and 5% of water contribute to green-house effect.