Changes

The main reasons for this lack of interest in discovering and producing natural gas were the low price of gas and the difficulty and high cost of transporting and distributing it. Natural gas can only be transported through pipelines or in liquefied form in special, very expensive cryogenic tankers. There was little incentive, therefore, to discover and produce natural gas if considerable distance separated the natural-gas deposits from the centers of consumption, and such was certainly the case for what we now know are some of the largest accumulations of natural gas in the world, in the former Soviet Union (FSU) and in the [http://www.britannica.com/EBchecked/topic/452764/Persian-Gulf Persian Gulf] region. During the 1950s, only in the United States was natural gas produced, transported, and consumed in substantial amounts. In 1950, the United States accounted for 90% of the world's natural-gas production and was still producing 75% of the world's total in 1960.<ref name=Masters_1993>Masters, C. D., 1993, World resources of natural gas-A discussion, ''in'' D. G. Howel, ed., [http://pubs.er.usgs.gov/publication/pp1570 The future of energy gases]: U.S. Geological Survey Professional Paper 1570, p. 607-616.</ref>

The main reasons for this lack of interest in discovering and producing natural gas were the low price of gas and the difficulty and high cost of transporting and distributing it. Natural gas can only be transported through pipelines or in liquefied form in special, very expensive cryogenic tankers. There was little incentive, therefore, to discover and produce natural gas if considerable distance separated the natural-gas deposits from the centers of consumption, and such was certainly the case for what we now know are some of the largest accumulations of natural gas in the world, in the former Soviet Union (FSU) and in the [http://www.britannica.com/EBchecked/topic/452764/Persian-Gulf Persian Gulf] region. During the 1950s, only in the United States was natural gas produced, transported, and consumed in substantial amounts. In 1950, the United States accounted for 90% of the world's natural-gas production and was still producing 75% of the world's total in 1960.<ref name=Masters_1993>Masters, C. D., 1993, World resources of natural gas-A discussion, ''in'' D. G. Howel, ed., [http://pubs.er.usgs.gov/publication/pp1570 The future of energy gases]: U.S. Geological Survey Professional Paper 1570, p. 607-616.</ref>

[[file:St54Ch3Figure29.jpg|thumb|300px|{{figure number|1}}World natural-gas production. From Salvador.<ref name=Salvador_2005>Salvador, Amos, 2005, Energy-A historical perspective and 21st century forecast: AAPG Studies in Geology 54, 208 p.</ref>]]

[[file:St54Ch3Figure29.jpg|thumb|300px|{{figure number|1}}World natural-gas production. From Salvador.<ref name=Salvador_2005>Salvador, A., 2005, Energy-A historical perspective and 21st century forecast: AAPG Studies in Geology 54, 208 p.</ref>]]

As shown in [[:file:St54Ch3Figure29.jpg|Figure 1]], the picture has changed dramatically in the last two or three decades as demand for natural gas has greatly increased: (1) markets for natural gas have developed in Europe, Japan, and elsewhere; (2) more gas was needed to be reinjected in oil fields in an advanced state of depletion; (3) the technologies of gas liquefaction and pipeline construction have improved, lowering the cost of long-distance natural gas transportation; and (4) environmental consciousness has become an important issue in the energy policy agenda, particularly in the developed world. Natural gas has indeed become the fuel of choice in most energy markets worldwide, particularly in the power-generation sector, where gas has been able to compete successfully with [[coal]] and has become the chosen fuel for the majority of new electric power-generating plants using combined-cycle gas turbines. Natural gas has been found to be clean, cost-competitive, and plentiful.

As shown in [[:file:St54Ch3Figure29.jpg|Figure 1]], the picture has changed dramatically in the last two or three decades as demand for natural gas has greatly increased: (1) markets for natural gas have developed in Europe, Japan, and elsewhere; (2) more gas was needed to be reinjected in oil fields in an advanced state of depletion; (3) the technologies of gas liquefaction and pipeline construction have improved, lowering the cost of long-distance natural gas transportation; and (4) environmental consciousness has become an important issue in the energy policy agenda, particularly in the developed world. Natural gas has indeed become the fuel of choice in most energy markets worldwide, particularly in the power-generation sector, where gas has been able to compete successfully with [[coal]] and has become the chosen fuel for the majority of new electric power-generating plants using combined-cycle gas turbines. Natural gas has been found to be clean, cost-competitive, and plentiful.