Global Warming

Global warming is the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation. Sunlight shines into the Earth's surface, where it is absorbed and then radiates back into the atmosphere as heat. In the atmosphere, “greenhouse” gases trap some of this heat, and the rest escapes into space. The more greenhouse gases are in the atmosphere, the more heat gets trapped. In another words, it is when heat tries to escape through the atmosphere but is blocked by “greenhouse” gases. Trapping heat causes the temperature to increase. An increase in global temperatures can in turn cause other changes, including sea level rise, and changes in the amount and pattern of precipitation. There may also be increases in the frequency and intensity of extreme weather events, though it is difficult to connect specific events to global warming. Other effects may include changes in agricultural yields, glacier retreat, reduced summer stream flows, species extinctions and increases in the ranges of disease vectors.