What is global warming, and how is it affecting the Earth and its population? Global warming is the observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades and the projected continuation of rising temperatures. The uncertainty in this range results from both the difficulty of predicting the amount of future greenhouse gas emissions and uncertainties regarding climate sensitivity.
For the last 10,000 years, the Earth's climate has been tremendously important to mankind. Today, nevertheless, major changes are taking place. People are performing an unintentional global experiment by changing the face of the entire planet. We are wiping out the ozone layer, which permits life to exist on the Earth's surface. All of these behaviors are adversely shifting the composition of the biosphere and the Earth's heat balance. If we do not slow down our use of fossil fuels and stop destroying, the forests, the world could become hotter than it has been in the past million years. Typical global temperatures have increased 1 degree Fahrenheit over the last century. If carbon dioxide and other greenhouse gases persist to spill into the atmosphere, global temperatures could rise 5 to 10 degrees by the middle of the next century.
An increase in global temperatures is grounds for other changes, including a rising sea level and changes in the amount and pattern of precipitation. These changes may enhance the occurrence and intensity of extreme weather events, such as floods, droughts, heat waves, hurricanes, and tornados. Further consequences include higher or lower agricultural yields, glacier retreat, reduced summer stream flows, the extinctions of species and increases in the variety of disease vectors. Global warming is likely to affect the number and magnitude of these events; nonetheless, it is difficult to connect particular events to global warming. Even though the focus of most studies is on the period up to...