... started to develop renewable energy re- sources such as active and passive solar energy, photovoltaic, wind, and ocean power systems, and biomass the only indigenous renewable energy resource ... population, and yet consumes about one quarter of the total global primary energy demand. Coal, oil, and natural gas contributed 23, 41, and 25%, respec- tively, to total U.S. energy demand in 1992, ... Of the three fossil fuels coal, oil, and natural gas coal contributed 78 and 60% to energy demand in China and India, while natural gas contributed only 2 and 6%, respectively. This suggests...