The greenhouse effect is a natural phenomenon that occurs on Earth, it is a process that results from the capacity of the atmosphere to absorb and emit the different heat fluxes received from solar radiation.
This process begins with the arrival of radiation from the Sun to the Earth's surface, where most of the energy is received as ultraviolet radiation. Of this energy, part is absorbed by the atmosphere (ultraviolet radiation), another part is reflected by clouds, and another reaches the planet's surface (as visible light) by heating it. Once this radiation has reached and warmed the Earth's surface, the Earth returns this energy in the form of infrared radiation (thermal energy) and is reflected and sent back to the atmosphere and space.
It should be noted that thanks to this process the temperature of the planet is compatible with life as we know it. However, pollution activities due to the fossil burning fuels and deforestation by humans have intensified the effects of this phenomenon, being the main cause of global warming.