Earth's Atmosphere

2. An example of how human activities limit or damage the climate.
3. An example of human activity that involves reactions with fuels.
4. Resources that are replaced at least as fast as they are used.
8. Metals that need to be extracted from ores can be d_________ using carbon.
12. Turning waste material into something new.
17. A phenomenon caused by the increasing gases in the atmosphere that trap heat from the Earth.
18. A greenhouse gas.
19. How plants and animals release carbon dioxide into the atmosphere.
20. Which atmospheric gas increased over time due to the action of photosynthesis.
21. Metals more reactive than carbon are extracted from their ores using e___________.

1. How plants take in carbon dioxide from the atmosphere.
5. The total amount of greenhouse gases generated by our actions.
6. Organisms that break down dead organic material.
7. This metal can be recycled.
9. How carbon is transferred from plants to animals.
10. A metal that is found naturally occurring in nature.
11. Rising average temperatures on Earth.
13. A fossil fuel resources that the Earth provides.
14. A resource that will run out.
15. Nature's way of reusing carbon atoms, travelling between the atmosphere and the Earth over and over again
16. Name the main gas in the atmosphere