International Commission on Irrigation & Drainage Commission Interationale des Irrigation et du Drainage



(9316) Greenhouse Effect
1 - Greenhouse gases effectively absorb infrared radiation emitted by the Earth’s surface, by the atmosphere itself due to the same gases, and by clouds. Atmospheric radiation is emitted to all sides, including downward to the Earth’s surface. Thus greenhouse gases trap heat within the surface-troposphere system. This is called the “natural greenhouse effect.” Atmospheric radiation is strongly coupled to the temperature of the level at which it is emitted. In the troposphere, the temperature generally decreases with height. Effectively, infrared radiation emitted to space originates from an altitude with a temperature of on average -19°C, in balance with the net incoming solar radiation, whereas the Earth’s surface is kept at a much higher temperature of on average 14°C. An increase in the concentration of greenhouse gases leads to an increased infrared opacity of the atmosphere, and therefore to an effective radiation into space from a higher altitude at a lower temperature. This causes a radiative forcing, an imbalance that can only be compensated for by an increase of the temperature of the surface-troposphere system. This is called the “enhanced greenhouse effect.” 2 – See 7196.

Related items you may like

Irrigation

Dictionary - Green Lawn Irrigation Terms

Sign up for newsletter

Follow us