The term "green house effect" refers to the rise in temperature that the earth experiences when certain gases in the atmosphere such as water vapour, carbon dioxide, nitrous oxide and methane trap incoming solar radiation from the sun. A certain degree of green house effect is necessary for human life. Without the greenhouse effect heat would escape into space and earth temperature would be 30*C colder. As a result life on earth would not be sustained. Scientists and others are concerned that the Earth is experiencing an enhanced greenhouse effect related to human activities. An increase in the amount of greenhouse gases in the Earth's atmosphere has led to a decrease in infra-red radiation back into space, causing an increase in the average Earth's temperature (global warming), which in turn may contribute to changes in climate.
