Gradual rise in average global temperature due to absorption of infrared radiation by increasing amounts of carbon dioxide in the air, which retards dissipation of heat from the earth°s surface. This phenomenon, which has been well documented, is ascribed to the burning of fossil fuels, especially coal, aided by aerosols and other contaminants. Definitive studies by NRC (1979) and NASA (1981) project a substantial increase in average temperature during the next century, perhaps as much as 3–4C. The increase of 1C reported to have occurred from 1900–1950 indicates that this has been going on for the last 100 years or more, coinciding with the industrial revolution. Since the CO2 concentration tends to be greatest at the poles (perhaps due to the absence of vegetation), it is probable that the ice caps there will deteriorate, with a concomitant rise in sea levels throughout the world. Other deleterious effects are also predicted, e.g., droughts in North America and central Asia caused by basic changes in rainfall distribution. As combustion of organic fuels is the underlying cause of this situation, reduction in their use is desirable wherever possible, combined with accelerated development of energy sources that do not produce carbon dioxide.
