4. Pollution sources

4.1 Power generation

Since the beginning of the 19th century, global energy consumption has grown more than exponentially up to the end of the 1970s. In pre-industrial times, the world's annual energy consumption was around 30 million toe (toe: tonne of oil equivalent). By 1900, it had risen to 520 million toe, 1,800 million toe by the early 1950s, and 8 billion toe by 1990. Between 1970 and 1990, however, the increase in energy demand slowed (growth of 2.3% vs. 5.2% between 1950 and 1970) following the rise in oil prices (1973 and 1979) and the adoption of measures to improve energy efficiency and reduce the growing demand for energy in developed countries (energy conservation). In absolute terms, world energy consumption in 1998 was around 8.7 billion toe, with coal accounting for...