Across
- 8. a natural fuel such as coal or gas, formed in the geological past from the remains of living organisms.
- 9. Greenhouse gases keep the Earth warm through a process called...
- 11. these released, carbon dioxide, steam, and ammonia.
- 13. the long-term heating of Earth's climate system
- 15. molecules in the atmosphere that were broken apart by sunlight, leaving nitrogen and hydrogen.
- 16. a series of regions in parts of the mesosphere and thermosphere where high-energy radiation from the Sun has knocked electrons loose from their parent atoms and molecules
- 19. occurs when a planet absorbs more energy from the sun than it can radiate back to space
- 20. the atmosphere that came from earth itself
Down
- 1. layer with the highest pressure
- 2. the lightest element that rose to the top of the atmosphere and much of it eventually drifted off into space.
- 3. take in carbon dioxide (CO2) and give off oxygen (O2)
- 4. emitted during agricultural and industrial activities, combustion of fossil fuels and solid waste, as well as during treatment of wastewater.
- 5. emitted during the production and transport of coal, natural gas, and oil.
- 6. water takes the form of an invisible gas
- 7. most produced greenhouse gas and responsible for the majority of global warming.
- 10. Carbon naturally moves from one part of the Earth to another through the...
- 12. where the earth gets its energy from,in forms of radiation
- 14. trap heat in the atmosphere, which makes the Earth warmer
- 17. global warming is caused mainly by...
- 18. the lightest elemnt
- 21. the amount of a particular gas in the air.