Coal consumption history

Looking back in the history, energy consumption of the world is constantly increasing. The trend of energy consumption in the world is shown in Fig. 1. In this diagram, oil, coal and natural gas has the largest consumption share of world primary energy, oil, coal, and natural gas are the three main sources. 

Fossil fuels, namely oil, coal, and gas, provide 85% of all the energy used in the United States. Renewable energy sources supply just 8%, most of which comes from hydropower and the burning of biomass while only 4% comes from geothermal sources. Fig. 2 shows the history and projections of the U.S. energy consumption by fuel sources for the period of 1970-2020. 

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