Environment

1. A gradual increase in world temperatures.
2. The cutting down of trees in a large area.
4. Energy gained of the heat inside the earth.
6. Fuels, such as gas, coal, and oil, that were formed underground from plant and animal remains millions of years ago
7. A long period when there is little or no rain.
9. Thick layers of ice that permanently cover an area on the Poles.
13. A layer above the earth that protects it from the sun’s ultraviolet light.
14. To damage something so badly that it cannot be used anymore.

1. The gradual warming of the earth because of heat trapped by carbon dioxide and other gases in the atmosphere.
3. The gas formed when carbon is burned, or when people or animals breathe out
5. When the earth has too many people for the amount of food, materials, and space available, we call that ................
8. Damage caused to water, air, etc. by harmful materials or waste.
10. ............ forms of energy can be produced as quickly as they are used.
11. Animals, plants that don't exist anymore.
12. A bear with white fur that lives in the Arctic.