Across
- 2. substance that pollutes something, especially water or the atmosphere.
- 3. all the inhabitants of a particular town, area, or country.
- 8. capable of being decomposed by bacteria or other living organisms.
- 13. the number of live births per thousand of population per year.
- 14. any of the almost spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere.
- 16. the natural home or environment of an animal, plant, or other organism.
- 17. a cooling of the water in the equatorial Pacific.
- 18. the action of coming to live permanently in a foreign country.
Down
- 1. the envelope of gases surrounding the earth or another planet.
- 4. irregularly occurring and complex series of climatic changes.
- 5. colorless unstable toxic gas with a pungent odor and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light
- 6. the weather conditions prevailing in an area in general or over a long period.
- 7. the ratio of deaths to the population of a particular area or during a particular period of time, usually calculated as the number of deaths per one thousand people per year.
- 9. the action of clearing a wide area of trees.
- 10. the regions of the surface, atmosphere, and hydrosphere of the earth
- 11. the process of making an area more urban.
- 12. the act of leaving one's own country to settle permanently in another; moving abroad.
- 15. fog or haze combined with smoke and other atmospheric pollutants.