| A | B |
|---|
| Global warming | Increase in the average global temperature of Earth. |
| Climate | Average weather pattern in an area over a long period of time; can be classified by temperature, humidity, precipitation, and vegetation. |
| El Nino | Climatic event that begins in the tropical Pacific Ocean; may occur when trade winds weaken or reverse, and can disrupt normal temperature and precipitation patterns around the world. |
| Adaptation | Any inherited structural or behavioral change that helps an organism survive in its particular environment. |
| Greenhouse effect | Natural heat-trapping feature that occurs when certain gases in Earth’s atmosphere, such as methane, CO2, and water vapor, trap heat and keep Earth warm enough to support life. |
| Deforestation | Destruction and cutting down of forests—often to clear land for mining, roads, and grazing of cattle—resulting in increased atmospheric CO2 levels. |
| Polar Zone | Climate zones that receive solar radiation at a low angle, extend from 66N and 66S latitude to the poles, and are never warm. |
| Temperate zone | Climate zones with moderate temperatures that are located between the tropics and polar zones. |
| Season | Short period of climate change in an area caused by the tilt of Earth’s axis as Earth revolves around the Sun. |
| Tropics | Climate zone that receives the most solar radiation, is located between latitudes 23N and 23S, and is always hot, except at high elevations. |
| Hibernation | Behavioral adaptation for winter survival in which an animal’s activity is greatly reduced, its body temperature drops, and body processes slow down. |
| Density current | Circulation pattern in the ocean that forms when a mass of more dense seawater sinks beneath less dense seawater. |
| Surface current | Wind-powered ocean current that moves water horizontally, parallel to Earth's surface, and moves only the upper few hundred meters of seawater. |
| Upwelling | Circulation in the ocean that brings deep, cold water to the ocean surface. |
| Wave | Rhythmic movement that carries energy through matter or space. |
