Across

6. The cutting or burning down of a large area of trees
8. A situation in which there is not enough food for a great number of people
11. A site where we dispose of rubbish by burying it
12. Being confined, not free
13. The accidental release of petrol in the sea
14. The waste product of car engines

Down

1. A large, destructive fire that spreads quickly over vegetation
2. When a particular species ceases to exist
3. A mix of smoke and fog that commonly appears over large cities
4. When too many people live in a particular area
5. Someone who is interested in or works for the protection of the environment
7. Rain that has become harmful due to chemical in the atmosphere
9. Energy created through the reaction of atoms
10. Natural fuels produced under the earth's surface over millions of years