Across
- 5. fuel natural sources of energy such as petroleum, coal or natural gas that form within the earth from ancient animal and plant remains
- 6. having too many people for the amount of food, materials, and space available in a given area, city or country
- 8. power produced by running or falling water, which may be used to produce electricity
- 10. the change in state from a solid to a liquid
- 12. an overflowing of water in a normally dry area
- 13. energy from a source that cannot be used up or run out, such as energy from wind or water
- 14. buses, trains and other forms of transport that are available to the public, charge set fares and run on fixed routes
- 15. energy from a source that can run out or that takes a long time for the earth to produce, such as oil and coal
Down
- 1. changes in weather patterns and the overall temperature of the earth
- 2. the total amount of grenhouse gases released into the atmosphere by a person, organization, event or product
- 3. the ability for something to be maintained or to keep going
- 4. a covering of ice over a large area, especially on the polar region of a planet
- 7. gases, such a carbon dioxide, methane and nitrous oxide, that trap heat in the atmosphere and make the earth warmer
- 9. to make something new from something that has been used before
- 11. energy derived from the sun in the form of solar radiation