Cites some of the evidence which suggests that the production of carbon dioxide and methane from human activities has begun to change the climate. Describes some measures which should be taken to stop or slow this progression. (RT)

States the foundations of the theory of global warming. Describes methodologies used to measure the changes in the atmosphere. Discusses steps currently being taken in the United States and the world to slow the warming trend. Recognizes many sources for the warming and the possible effects on the earth. (MVL)