The Greenhouse Effect
As the sun’s rays come towards the Earth, gases in our atmosphere trap infrared radiation (heat) and warm our planet. We call this the "greenhouse effect" since these gases act like the glass in a greenhouse. The main greenhouse gas is CO2. Without CO2 and the other greenhouse gases, our planet would be too cold to support life. However, if there is too much greenhouse gas in the atmosphere, the Earth becomes too hot. This overheating of the Earth is called "global warming".
Every day, there is a decreasing number of trees to absorb an increasing amount of CO2. As a result, the Earth is heating up! New records have been set in nine of the past 11 years for higher global temperatures, and 1997 was the hottest year on record. As the Earth’s temperature rises, polar ice caps melt, weather patterns change, flooding and droughts are more frequent, and ocean levels rise. Farming, forestry, fishing and plant and animal habitats are all affected. Coastlines, such as the land around Tokyo Bay, will disappear as they are covered with water. If the current rate of global warming continues, by 2050 the Earth will be 1.5 to 4.5 degrees hotter than it is now. If this seems to be only a small increase, consider this: when the Earth was only 5 degrees cooler than now, ALL of North America was covered in ice!