World recoverable coal reserves

The worldwide coal production and consumption in 1998 were 5043 and 5014 million short tons, respectively. The known world recoverable coal reserves in 1999 were 1087 billion short tons (AER, 1999 lEA, 2000). Coal reserves are rather evenly spread around the globe 25% ate in the USA, 16% in Russia, and 11.5% in China. Although coal is much more abundant than oil and gas on a global scale, coalfields can be depleted in a region. The known world recoverable coal reserves in 1999 were 989 billion tons. 

Pig. I. Wortd recoverable coal reserves (millions of short ions). (World Energy Council)... 

The United States contains about one-third of the world s coal reserves, and coal represents over 90 percent of U.S. proven reserves of fossil fuels. Recoverable reserves of U.S. coal are estimated to be 250 billion tons. Bituminous coals (with a heating value of 10,GOO-15,000 BTU/lb) comprise nearly one-half of total U.S. coal reserves. Eastern U.S. coals are generally bituminous. Western and southwestern U.S. coals are mainly sub-bituminous... 

One-quarter of the world s coal reserves are found within the United States, and the energy content of the US coal resources exceeds that of all the world s known recoverable oil. Coal is also the workhorse of the nation s electric power indnstry, supplying more than half the electricity consnmed by Americans. 

The demand for energy is continually increasing and the highest energy consumption in the world occurs in the United States. In 1989 consumption totaled 8.6 x 10 MJ (81.3 x 10 Btu) or 11.7 metric tons of coal-equivalent per capita (85). World recoverable reserves were about 120 times the annual coal production in 1988 and about 10 times that for the additional reserves beheved to be in place (1). Estimated coal consumption reduces the known recoverable reserves at about 1%/yr. Whereas the use of bituminous coal is expected to continue to increase in terms of tonnage, the percentage of coal used in the United States has stabilized as shown in Table 11. 

Coal is the most abundant and most economical fossil fuel resource in the world. Proven coal reseiwes exceed 1 trillion tons, and indicated reserves are estimated at 24 trillion tons. Coal is found in eveiy continent of the world, including Antarctica, although the largest quantities of coal are in the Northern Hemisphere. Coal is mined in some sixty countries in nineteen coal basins around the world, but more than 57 percent of the world s total recoverable reserves are estimated to be in the United States, and China, which together account for more than two-thirds of the world s coal production. 

Fig. 1. The combined world fossil fuel use curve shows the sum of the historical worldwide production of oil, gas and coal up to 1990 (Barabba, 1989 Taylor, 1989 Kilgore, 1993 West, 1993). The combined world fossil fuel production is projected into the future base on proved reserves of oil and gas, and an estimate of known recoverable coal. The units are in quads (10 BTU).

Hard coal, representing over 50% of the fossil raw materials, is the carbonaceous material with by far the greatest availability. Confirmed world resources of hard coal are around 6,900 billion t of these, some 550 billion t can be recovered by current mining techniques. Brown coal deposits total some 6,500 billion t, of which 430 billion t are recoverable. In comparison with coal reserves, economically recoverable oil reserves are only 95 billion t, and natural gas deposits 90,000 billion m (around 72 billion t). 

It is estimated that 25% of the world s recoverable coal (coal that can be readily mined) is located in the United States. As such, it is believed that the United States has enough natural resources to meet all of its energy needs for at least 200 years. To provide some additional perspective, consider the fact that these natural resources contain more than double the energy contained in all of the combined oil reserves in the Middle East. 

Table 2. World Estimated Recoverable Reserves of Coal in Billions of Metric Tons...

Coal, tar, and heavy oil fuel reserves are widely distributed throughout the world. In the Western hemisphere, Canada has large tar sand, bitumen (very heavy cmde oil), and coal deposits. The United States has very large reserves of coal and shale. Coal comprises ca 85% of the U.S. recoverable fossil energy reserves (6). Venezuela has an enormous bitumen deposit and Brazil has significant oil shale (qv) reserves. Coal is also found in Brazil, Colombia, Mexico, and Pern. Worldwide, the total resource base of these reserves is immense and may constitute >90% of the hydrocarbon resources in place (see... 

The importance of a coal deposit depends on the amount that is economically recoverable by conventional mining techniques. The world total recoverable reserves of lignitic coals were 3.28 x 10 metric tons at the end of 1990 (3), of which ca 47% was economically recoverable as of 1994 (Table 4). These estimates of reserves change as geological survey data improve and as the resources are developed. 

Comprehensive reviews of energy sources are pubflshed by the World Energy Conference, formerly the World Power Conference at six-year intervals (83). The 1986 survey includes reserves and also gives total resources. In 1986 the total proven reserves of recoverable soHd fuels were given as 6 X 10 metric tons. One metric ton is defined as 29.2 x 10 MJ (27.7 x 10 Btu) to provide for the variation of calorific value in different coals. The total estimated additional reserves recoverable and total estimated additional amount in place are 2.2 x 10 and 7.7 x 10 metric tons, respectively. These figures are about double the 1913 estimates, primarily because significantly increased reserves have been indicated for Russia. 

In his book, Hubbert s Peak The Impending World Oil Shortage, Deffeyes (2001) argues that the production of anthracite coal in Pennsylvania followed the Hubbert curve. Coal production in Pennsylvania commenced in 1830 and grew exponentially until production peaked in 1920 when half of the recoverable reserves had been extracted. Production then declined, with the exception of a spike in production during World War II. By 1980 production was nearing zero. 

The distribution of coal in the world is given in Table 2.1. The recoverable reserves consist of the coal which can be economically mined with presently known technology and conditions. The proven reserves are the coal known to be present, within +20%, by extensive drilling and experience and are about twice the recoverable reserves. The estimated total world coal resources are about eight times larger and are based on geologically favorable formation within the earth s crust and on previous experience within the coimtries concerned. It excludes under sea or under ice sites. 

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