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Resources not infinite

In the last 25 years global primary energy consumption has increased by around 60%. In 1998, the primary energy consumption was 13.8 billion tons of coal equivalent (TCE). The share of fossil fuels in primary energy consumption is 80%. The share of oil in total primary energy consumption is about 36%, natural gas accounted for 20% and coal 24%.

Because of world population growth and the growing Traffic needs and transport tasks especially in so-called emerging markets and developing countries sustained future growth of the world energy consumption is expected. By 2020, the International Energy Agency (IEA) expects an energy consumption of 19.9 billion tons of coal equivalent (TCE) per year.

 Adequate supplies of fossil fuels to meet growing energy needs are only available if the „unconventional reserves“ in the balance sheet are taken into account (see table).

Table: Fossil fuel reserves in billion tons of coal equivalent (as of 1998)

Sichere Reserven

Zusätzliche Vorräte




Unkonventionelle Erdölvorkommen






Unkonventionelle Erdgasvorkommen






Source: Energy Study of the Federal Institute for Geosciences and Natural Resources, Hannover 1999

Unconventional reserves are proven or suspected reserves, which are obtained with a higher technical complexity or from unconventional sources. These include, for example, the oil reserves in oil shale and oil sands, and natural gas from tight reservoir rocks and coal bed methane gas hydrates and coal. In both the conventional and unconventional energy resources it has to be distinguished  between stocks and secure additional supplies. The latter are the estimated additional recoverable reserves, which are estimated based on assumption of deposits.

 Particularly striking is the large difference between the safe and additional reserves of unconventional gas resources. Also striking that on the large amount of  safe supplies of coal and the substantial additional supplies of coal. The coal reserves are probably enough for several centuries. Greater use of this energy source, however, would lead to the higher specific CO2 emissions of coal and to an intensification of the greenhouse effect.

1 kg SKE = 29,305 kWh = 8.14 kJoule