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An increase in the near surface temperature of the Earth. Global
warming has occurred in the distant past as the result of natural
influences, but the term is most often used to refer to the warming
predicted to occur as a result of increased emissions of greenhouse
gases. Scientists generally agree that the Earth's surface has warmed
by about 1 degree Fahrenheit in the past 140 years. The
Intergovernmental Panel on Climate Change (IPCC) recently concluded
that increased concentrations of greenhouse gases are causing an
increase in the Earth's surface temperature and that increased
concentrations of sulfate aerosols have led to relative cooling in some
regions, generally over and downwind of heavily industrialized areas.....
Edited 5/10/09 by ABCNewsModerator1