Let us examine the greenhouse effect first from the point of view of the glass enclosure so familiar to you at florists or plant nurseries. The underlying principle behind these buildings is that glass allows visible light to pass through, 10 but it does not allow infrared radiation to be transmitted as readily. During the day, sunlight passes through the windows of a greenhouse and is absorbed by the earth, walls, and vegetation inside the structure. These objects then re-radiate this energy in the form of infrared radiation,‘ but this radiation is now trapped because it cannot escape through the glass. As a result, the temperature 15 of the interior rises.