New trends in physics teaching, v.4; The ... - unesdoc - Unesco

New Trends in Physics Teaching IV
Energy: facts and figures
T. D. R. HICKSON
In this brief survey of the energy situation in the world today, an attempt has been made to draw
together information from a wide variety of sources so as to produce data with which most people
wil agree. To expect total reliability is to dream. No matter how reliable a source may appear to
be, sooner or later it is likely to be found to conflict with another authority. All that can be
hoped for is to make comparisons and to discern trends.
Quantities of energy have been quoted in kilograms of coal equivalent (kgce) or millions of
tonnes of coal equivalent (Mtce). This seems to be most appropriate as the world enters a second
era of growing importance for coal.
Human progress has always been closely associated with the availability of energy. Indeed an
early energy crisis occurred in the late sixteenth century. Holland and England were both affected
by an acute shortage of fuel wood. As a consequence of a general rise in mercantile prosperity,
more and more timber was needed for ships, for houses, for iron-smelting, for firewood, for
salt-making, soap-boiling, brewing and for domestic uses. Although timber could be imported,
the solution which lay most readily to hand was coal. Thus was born the first Industrial Revolution
and, with it, an acceleration in the rate of growth of energy use.
Although natural gas has been used on a small scale for a very long time, it was the introduction
at the end of the eighteenth century of synthetic gas, produced from coal, for lighting that really
began the exploitation of this fuel. In the middle of the present century, large deposits of natural
gas were found. Once the problems of transport over large distances were solved, natural gas
became an important source of energy.
Finally, the discovery of oil in the late nineteenth century coupled with the development of
the internal combustion engine - and its use in road transport - completed the trio of fossil
fuels upon which twentieth century industrial development has depended.
WORLD ENERGY DEMAND AND SUPPLY
When considering the way in which the nations of the world consume energy, two points are
obvious. The first is that, in spite of political and economic upheavals, the rate of consumption
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