Solar radiation, greenhouse effect

Greenhouse effect The retention of heat by the earth and the atmosphere due to certain gases being transparent to incoming solar radiation but opaque to the longer-wave radiation back from the earth. 

The greenhouse effect is a natural phenomenon whereby the earth s atmosphere is more transparent to solar radiation than terrestrial infixed radiation (emitted by the earth s surface and atmosphere). Consequently, the planet s mean surface temperature is about 33 K higher than the planet s radiative equilibrium temperature (the temperature at which the earth comes into equilibrium with the energy received from the sun). 

Greenhouse effect The warming of Earth s atmosphere as a result of the retention of solar radiation. This retention is possible because insolation absorbed by the land and ocean is radiated back to the atmosphere as IR energy. This energy is absorbed by atmospheric gases and then radiated from them as heat. 

Ramanathan, V., and A. M. Vogelmann, Atmospheric Greenhouse Effect, Excess Solar Absorption and the Radiation Budget From the Arrhenius/Langley Era to the 1990s, Ambio, 26, 38-46 (1997). 

A greenhouse gas is any component of tbe atmosphere that allows visible solar radiation to reach the Earth s surface but prevents invisible infrared radiation (beat) from escaping back into outer space. This mimics the warming action of a greenhouse. If it were not for the atmosphere s greenhouse effect, Earth s average surface temperature would be a chilly -i8°C. 

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