Basics of Environmental Science

126 / Basics of Environmental Science

of it exported. Coal is plentiful, but clearly not inexhaustible, and it might have occurred to people in

the early years of this century that if the country continued to export this strategically important

resource at that rate, the day would come when Britain had no choice but to import the fuel needed

to power its industry and heat its homes. They might have felt it more sensible to restrict production

and conserve coal for future needs. Today, matters appear rather different to those who might have

benefited from such a conservation policy. In 1982, British mines produced about 125 million tonnes

(Mt) of coal and the country consumed 111 Mt. In 1995, 52.6 Mt was produced and 76.2 Mt consumed

(the difference was imported). Despite Britain’s vast reserves, production and consumption declined,

mainly because of a switch from coal to natural gas for power generation. Had the British decided

years ago to restrict mining in order to conserve resources, the decision would have been wrong-

headed. The loss of export earnings would have been economically damaging and the reduction in

mine output would have caused unemployment. The decision would have caused real hardship, all to

conserve a material for which a later generation had little use.

Relate this to the case of the United States, where coal mining and use are still increasing. There,

between 1982 and 1992, coal production increased from 756 Mt to 905 Mt and consumption from

639 Mt to 808 Mt. Rising demand stimulated the search for and identification of new deposits that

could be mined under the prevailing economic, political, and environmental conditions. Such identified

deposits constitute ‘reserves’ and they increased, from 223 Mt in 1982 to 240 Mt in 1992.^1

Remembering the British experience, how sensible would it be for the United States to restrict coal

mining in order to conserve coal for future generations? If the case for conserving coal is dubious,

how many other materials and fuels might be of similarly doubtful future value?

Tonne for tonne, natural gas yields more energy than coal and releases fewer gaseous and no particulate

pollutants. Fears of its imminent exhaustion may be unfounded. Conventional reserves may be much

larger than was once supposed, and there may be a novel source: natural gas hydrate. This is a solid

substance comprising a cage of water ice containing methane, technically a water clathrate of methane.

Figure 3.18 Structural oil and gas traps