science

2. The total human presence on earth
6. Colorless and odorless gas that makes up a portion of earth's atmosphere, 1 carbon 2 oxygen
9. The crust and mantle of the earth
13. All the water on the earth's surface
15. Matter that sits at the bottom of a liquid over a long period of time
16. Form of energy resulting from the existence of charged particles
17. A liquid mixture of hydrocarbons that is present in certain rocks
19. The long-term weather conditions of a region
20. A natural fuel such as coal or gas formed from past organism that died

1. The amount of carbon dioxide emitted due to the consumption of fossil fuels
3. Long-term shifts in temperatures and weather patterns
4. The rocks that make up the planet
5. A region on earth occupied by living organisms
7. The gases that envelope the earth
8. A forest, ocean, or other natural environment viewed in terms of its ability to absorb carbon dioxide from the atmosphere
10. Process of plants that intake Carbon dioxide and expel oxygen, the plant generates food and water for the plant
11. Colorless and odorless gas that makes up the second part of natural gas
12. A white or grayish solid produced by roasting calcium carbonate, its second name is quicklime
14. Flammable gas, consisting largely of methane and other hydrocarbons
18. Colorless and odorless gas that makes up a part of natural gas