Greenhouse gases in the Earth's atmosphere absorb the infrared radiation from the sun andrelease it. Much of the released heat reaches the earth, along with the heat of the sun that hasalready penetrated the atmosphere. Now both solar heat and radiated heat are absorbed by theearth and released. Some are reabsorbed by greenhouse gases to perpetuate the cycle. Theproblem is that the more of these gases exist, the more heat is prevented from escaping intospace and, therefore, the earth is heated. This increase in heat is called the greenhouse effect.