ABSTRACT
In 1999, world consumption of fossil fuels increased 0.1 percent, to just above 1997 levels. 1 (See Figure 1.) Although usage expanded more than fourfold over the last 50 years, average annual growth rates slowed from 5.7 percent during the 1950s to 0.7 percent during the 1990s. 2 Divergent trends for individual fuels, meanwhile, reflect an ongoing shift in the global energy system from solid to liquids to gases.
