The Earth’s surface warms up during the day and cools down at night, releasing the heat in the form of infrared radiation IR out of the atmosphere into space. But before all these infrared radiation can escape out of the atmosphere into the space, they are absorbed by greenhouse gases (GHG’s) present in the atmosphere. The absorption of these radiations by greenhouse gases makes it possible to keep this planet warm for humans. Without Greenhouse effect, the temperature of this planet would be lesser by 30 degree Celsius and this would be too cold for us to survive.