The greenhouse effect is a natural process that warms the Earth's surface.
When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
That trapping of heat is known as the greenhouse effect.
EXPLANATION:
Radiation heat transfer happens in gases because of the movement of atoms and molecules.
Greenhouse gases in the atmosphere absorb the infrared radiations of higher wavelengths and warm the atmosphere.