In general, the Earth releases energy back to the atmosphere through reflection, evaporation, and radiation. The Earth gets energy from the sunlight, part of which it absorbs, while part it reflects backwards, thus giving energy to the atmosphere. Also, the heating up of the Earth by the absorbed sunlight, radiates back in the lower layers of the atmosphere, again giving back energy to it. The water vapor is another way in which the Earth gives back energy tot he atmosphere as through the evaporation, the water vapor gets into the lower parts of the atmosphere and gives energy to it.
