The GreenHouse Effect

The Earth receives energy from the Sun in the form of electromagnetic radiation. Most of the radiation is in the visible spectrum which is of a shorter wavelength. The visible light with solar energy passes through the gases in the atmosphere without much effect. The longer wavelength infrared radiation on reaching Earth is reflected back to space and get trapped in the atmosphere.

The gases in the atmosphere absorb some of the infrared radiation and reflect some back to earth.

The contributing gases in the atmosphere that add to global warming are methane, nitrous oxide, carbon dioxide, water vapour and chlorofluorocarbons (CFCs) from aerosols. These gases are also called Greenhouse gases (GHG). Of these gases, the concentration of carbon dioxide is the most being more than 60%. The CFCs although making up only about 10% of the total greenhouse gases (GHG) has the most capacity to absorb the infrared rays.Methane makes 25%  of the (GHG) but absorbs 20-30% of the infrared rays.

These gases keep the Earth warm enough to support life by preventing the heat from the solar radiation. They absorb the radiation and re radiate back to Earth and prevent the trapped gases from escaping back to Space.

Under natural circumstances that is good as it provides necessary heat for living things to survive. However due to high concentrations of these gases from man’s activities (vehicular emissions, industrial effluents, agricultural activities and other human activities), more gases are trapped in the atmosphere.

The extra heat cause the Earth to heat up as it increases the Earth’s surface temperature. This is what is called Global Warming.

It is harmful to the environment as it changes the climatic patterns and threaten the very existence of life on Earth.