Global Warming, an increase in the earth’s temperature due to the use of fossil fuels and certain industrial and agricultural processes leading to a buildup of “greenhouse gases” (principally carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and water vapor) in the atmosphere. Since 1896 it has been known that these gases reduce the escape of the earth’s infrared radiation into space and thus function to maintain the earth’s relatively warm temperature. (This is called the greenhouse effect.) Although there is broad agreement thhat human activity, such as burning fossil fuels, has reached a scale that is beginning to influence climate, there is much uncertainty and debate over how much and how fast the climate will warm. Elevated global temperatures could result in coastal flooding and the shifting of major climatic zones and may have serious implications for agricultural productivity.
Since 1850 there has been a mean rise in global temperature of approximately 1 Celsius degree (approximately 1.8 Fahrenheit degrees) and a 28 percent rise in carbon dioxide leevels. While most scientists link this temperature rise to the increase in carbon dioxide levels, other scientists argue that this temperature rise could just be part of a natural fluctuation; such fluctuations have been recorded for tens of thousands of ye
A number of international efforts have been undertaken to reduce greenhouse-gas emissions, the most recent of which occurred in December 1997. Delegates to an international summit on global warming in Kyōto, Japan, approved an agreement, known as the Kyōto Protocol, requiring industrialized nations to limit emissions of greenhouse gases. The pact, signed by officials from 160 countries, requires 38 industrialized na