| A | B |
|---|
| What do scientists believe CFCs are a problem? | They think that a "hole" in the ozone layer over the South Pole has been caused by this. |
| What blocks many of the short waves? | the Earth's atmosphere |
| What does the burning of coal, oil, and wood create? | carbon dioxide |
| Do greenhouse gases let Earth's heat escape into space? | no |
| What do scientists think an increase in the greenhouse effect will change? | Earth's climates |
| Earth's surface gives off energy in the form of ___. | infrared waves |
| What can harm people when it is near the ground? | ozone |
| What can break down an important atmospheric gas? | CFCs |
| What can cause skin cancer? | UV rays |
| What can trap heat from the ground? | greenhouse gases |
| Should you protect yourself from UV radiation? Why? | Yes, not to get sunburned. |
| Can you prevent sunburns? How | Yes, by wearing a hat, sunglasses, putting on more clothes, staying out of the sun. . . . |
| Might CFCs from spray cans have caused the hole in the ozone layer? | yes |
| How can the ozone be both helpful and harmful? | Helpful because it blocks harmful UV rays from reaching the earth's surface. Harmful because poisonous when breathed. |
| Why don't most harmful UV rays reach the earth's surface? | They are stopped at the ozone layer. |
| What are the greenhouse gases? | carbon dioxide and water vapor |
| Where is harmful UV found? | ozone layer |
| What are the two main gases layered in the Earth's atmosphere? | nitrogen and oxygen |
