The greenhouse effect is the process in which the emission of infrared radiation by the atmosphere warms a planet’s surface.
The name comes from an analogy with the warming of air inside a greenhouse compared to the air outside the greenhouse.
The Earth’s average surface temperature is about 33°C warmer than it would be without the greenhouse effect.
In addition to the Earth, Mars and especially Venus have greenhouse effects. The Earth receives energy from the Sun in the form of radiation.
The Earth reflects about 30% of the incoming solar radiation.