| A | B |
|---|
| deforestation | the destruction of forests resulting from human activity |
| direct harvesting | the destruction or removal of species from their habitats |
| energy flow | food chains, food webs, and energy pyramids illustrate how energy flows through ecosystems |
| fossil fuel | fuels such as coal and oil that formed from the remains or organisms that lived millions of years ago |
| global warming | carbon dioxide traps heat on the Earth in the greenhouse effect, humans burn fossil fuels which puts extra carbon dioxide in the atmosphere, so extra heat is trapped on the Earth |
| industrialization | the development of an economy in which machines produce many of the products people use |
| ozone shield (layer) | the layer of ozone gas in the upper atmosphere that blockes ultraviolet radiation from the sun |
| pollution | a harmful change in the chemical substances in the soil, water, or air |
| water cycle | water evaporates, condenses, precipitates, and collects (groundwater, runoff) continuously |
| acid rain | burning of fossil fuels adds sulfur and nitrogen to the atmosphere which combines with water to form acid rain |
