1 The earth__ naturally___ by rays (or radiation) from the sun which pass through the earth's atmosphere. 2 The Sun's rays__ __________ back out to space again. 3 The atmosphere___ ________ up of layers of gases, some of which 'greenhouse gases'. These "greenhouse gases" are natural and keep the earth at the right temperature for animals, plants and humans to survive (60°F/16°C). 4 So some global warming is good. But if extra greenhouse gases___ ________ and too much heat____ _______ the thermal blanket gets thicker " in the earth's atmosphere. That's when global warming's bad
