Climate change:

2. Protective layer in atmosphere that shields earth from UV radiation.
4. Damage done to a habitat that results in the loss of resources that organisms need to survive, like food, water, and shelter
6. The number of people in an area exceeds the capacity of the environment to support life at a decent standard of living.
8. The ability to keep in existence or maintain. A sustainable ecosystem is one that can be maintained
11. a gas that contributes to the greenhouse effect by absorbing infrared radiation, e.g., carbon dioxide and chlorofluorocarbons.
13. effect the natural warning of the surface and lower atmosphere of earth that occurs when carbon dioxide, water vapor, and other gases in the air absorb and reradiate infrared radiation.
15. Species that serve as early warnings that a community or ecosystem is being degraded.
17. change A change in temperature, precipitation, or wind of a region, lasting for an extended period of a decade or longer.
18. warming An increase in the average temperature of the earth's atmosphere (especially a steady increase that causes changes in climate).
19. Fuels Coal, oil, natural gas, and other fuels that are ancient remains of plants and animals.
20. The effect of humans on an ecosystem
22. A natural resource that can be replaced at the same rate at which the resource is consumed

1. Release of harmful materials into the environment
3. the variety of life in the world or in a particular habitat or ecosystem.
5. species a species that has died out and no individuals are left.
7. A species whose numbers are so small that the species is at risk of extinction
9. nina a cooling of the ocean surface off the western coast of South America, occurring periodically every 4 to 12 years and affecting Pacific and other weather patterns.
10. The removal of trees faster than forests can replace themselves.
12. A species that influences the survival of many other species in an ecosystem
14. a resource that cannot be reused or replaced easily (ex. gems, iron, copper, fossil fuels)
16. nino a change in the water temperature in the Pacific Ocean that produces a warm current, a weather pattern created by the warming of the waters off the west coast of South America, which pushes warm water and heavy rains toward the Americas and produces drought conditions in Australia and Asia.
21. species that enter new ecosystems and multiply, harming native species and their habitats