1 \u2013 A greenhouse is a building built of any material that passes sunlight , usually glass , or plastic.<\/p>\n\n\n\n
2 \u2013 People grow tomatoes and flowers and other plants in them. A greenhouse stays warm inside , even during winter , the heat is trapped by the glass and can\u2019t escape.<\/p>\n\n\n\n
3 \u2013 The Earth gets energy from the sun in the form of sunlight. The Earth\u2019s surface absorbs some of this energy and heats up. That\u2019s why the surface of a road can feel hot even after the sun has gone down\u2014because it has absorbed a lot of energy from the sun.<\/p>\n\n\n\n
4 \u2013 The Earth cools down by giving off a different form of energy , called infrared radiation. But before all this radiation can escape to outer space , greenhouse gases in the atmosphere absorb some of it , which makes the atmosphere warmer. As the atmosphere gets warmer , it makes the Earth\u2019s surface warmer , too.<\/p>\n\n\n\n
5 \u2013 Because gases in the Earth\u2019s atmosphere also let in light but trap heat , many people call this phenomenon the \u201cgreenhouse effect.\u201d<\/p>\n\n\n\n
6 \u2013 Greenhouse gases keep the Earth warm through a process called the greenhouse effect.<\/p>\n\n\n\n
7 \u2013 Earth\u2019s atmosphere does the same thing as the greenhouse. Gases in the atmosphere such as carbon dioxide do what the roof of a greenhouse does. During the day , the Sun shines through the atmosphere. Earth\u2019s surface warms up in the sunlight. At night , Earth\u2019s surface cools , releasing the heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere.<\/p>\n\n\n\n
8 \u2013 And this is a natural process of maintaining the average temperature of our planet , and keeping it warm.<\/p>\n\n\n\n
9 \u2013 If it were not for greenhouse gases trapping heat in the atmosphere , the Earth would be a very cold place.<\/p>\n\n\n\n
10 \u2013 Without the greenhouse effect , the Earth would not be warm enough for humans to live. But if the greenhouse effect becomes stronger , it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans , plants , and animals.<\/p>\n\n\n\n