Environmental Crossword

4. food waste that can be turned into soil
6. all the organisms of a certain kind in a particular place
12. the world's largest carbon sink
13. caused by human activity
14. gas with unpleasant odour produced from burning fossil fuels containing sulfur
16. unwanted, or unusable waste
18. the natural warming of the Earth's surface and lower atmosphere
19. amount of carbon dioxide released into the air because of one's own energy needs
21. formed when oxygen reacts with nitrogen as temperature increases, produced from burning fossil fuels, smoking, etc.
22. gases that trap heat in the atmosphere

1. clear, odourless, poisonous gas produced by car engines, smokers etc.
2. the long-term pattern of weather
3. the cycling of carbon molecules between oceans, air, organisms, and rocks
5. tiny pieces of solid matter suspended in air, such as ash, manure, etc.
7. produced almost exclusively by living (or once-living) things
8. layered into four regions: thermosphere, mesosphere, stratosphere, troposphere
9. the substance or material that causes harm to the environment
10. waste that can be converted into something else
11. the introduction of harmful substances or materials into the environment
15. increased global temperatures as a result of increased greenhouse gases
17. the conditions of the atmosphere over a short-term basis
20. not produced by living things