From MARK LAWSON
The article speculating on the use of coal as a substitute chemical
feed stock (‘Rich seams for chemicals’, 23 January) was correct in pointing
out that at present the world has reserves of oil equivalent to 40 (actually
44) years worth of production.
What the authors neglected to mention – and this is a sad fact for Australia
as the world’s largest exporter of coal – is that in 1965 the estimate was
35 years. The extra nine years added since are largely the result of the
puzzling fact that the annual growth in proven reserves, worldwide, almost
always exceeds production.
Further, should the figure ever start declining, the resulting price
increase should make it worthwhile for oil producers to extract more oil
from old fields (only a fraction of the oil in each field is extracted at
present) and look at other expensive substitutes such as shale oil – oil
locked in sedimentary rock. There are huge deposits of shale oil.
Demand for oil could always increase rapidly, especially when the economies
of the Eastern bloc and China finally develop, but any such increase may
well be a passing phase. Energy intensity – energy used per unit of GNP
– has long been declining in advanced economies.
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All this means that while there must be an ultimate end to oil reserves,
that end is nowhere in sight. Coal may be very useful as a substitute chemical
feed stock and fuel, but the problem of converting coal to such uses is
not an urgent one.
Mark Lawson Sydney, Australia
