Across
- 5. the envelope of gases surrounding the earth or another planet
- 6. the ratio of deaths to the population of a particular area or during a particular period of time
- 10. unusually warm ocean temperatures in the Equatorial Pacific
- 12. the action of clearing a wide area of trees
- 14. the weather conditions prevailing in an area in general or over a long period
- 16. a substance that pollutes something, especially water or the atmosphere
- 17. fog or haze combined with smoke and other atmospheric pollutants
- 18. a natural resource which will replenish to replace the portion depleted by usage and consumption
- 21. the specified extent or degree to which an area is or has been populated
- 22. capable of being decomposed by bacteria or other living organisms
- 24. an irregularly recurring upwelling of unusually cold water to the ocean surface along the western coast of South America
- 25. the number of people living in each unit of area
Down
- 1. the total number of children that would be born
- 2. the process of making an area more urban
- 3. the regions of the surface, atmosphere, and hydrosphere of the earth
- 4. one of two types of biological and ecological succession of plant life
- 7. a colorless unstable toxic gas with a pungent odor and powerful oxidizing properties
- 8. any of a class of compounds of carbon, hydrogen, chlorine, and fluorine, typically gases used in refrigerants and aerosol propellants
- 9. a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide
- 11. the action of coming to live permanently in a foreign country
- 13. ratio betw een the number of live-born births in the year and the average total population of that year
- 15. an area that was previously occupied by living things is disturbed, then re-colonized following the disturbance
- 19. the act of leaving one's own country to settle permanently in another
- 20. the factor that limits the reaction rate in any physiological process governed by many variables
- 23. a substance that pollutes something, especially water or the atmosphere