Greenhouse effect
The greenhouse effect refers to the change in the thermal equilibrium temperature of a planet or moon by the presence of an atmosphere containing gas that absorbs and emits infrared radiation.[1] Greenhouse gases, which include water vapor, carbon dioxide and methane, warm the atmosphere by efficiently absorbing thermal infrared radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. As a result of its warmth, the atmosphere also radiates thermal infrared in all directions, including downward to the Earth’s surface. Thus, greenhouse gases trap heat within the surface-troposphere system.[2][3][4][5] This mechanism is fundamentally different from the mechanism of an actual greenhouse, which instead isolates air inside the structure so that heat is not lost by convection and conduction, as discussed below.
