Earth's Resources

2. A resource that takes millions of years to form.
3. A 1970 law that limited air pollutants and improved air quality in the U.S.
4. Water that flows over the land rather than seeping into the ground, often carrying pollutants.
7. An energy source that is nonpolluting and has free ‘fuel.’
8. Formed when eroded heavy minerals settle quickly from moving water.
12. The careful use of resources.
14. Site of a major nuclear disaster in 1986 due to reactor explosions.
16. Hydrocarbon used as an energy source, including coal, oil, and natural gas.
18. Electricity generated by falling water that drives turbines.
20. Process where uranium nuclei are bombarded with neutrons to release energy.

1. The unnatural warming of Earth’s lower atmosphere due to increased carbon dioxide.
5. Pollution from a known and specific location.
6. A useful metallic mineral that can be mined for profit.
9. An energy source that could substitute dwindling petroleum but has significant environmental drawbacks.
10. A renewable energy source that could meet 5-10% of U.S. electricity demand in the next 50 to 60 years.
11. Energy harnessed by constructing a dam across a bay or estuary with a large tidal range.
13. Energy harnessed by tapping natural underground reservoirs of steam and hot water.
15. A type of resource that can be replenished over short time spans, such as months or years.
17. The process of collecting and processing used items to make new products.
19. Partly decomposed organic material used as fertilizer.