|Global Environmental History in the Age of Fossil Fuels
II. Fossil Fuels
The acquisition of fire and language made our ancestors fully human. The adoption of agriculture laid the basis for civilisation and states. The adoption of fossil fuels made us modern. Each of these was a great leap in the human career, in the sense that each allowed, indeed encouraged, greater complexity in human society and in the human relationship with the earth.
For most of human history, our ancestors used, per capita, only 1-2% of the energy we use today. For all practical purposes, they were limited to what they could ingest in the way of chemical energy in their food, which their bodies converted to heat and mechanical or kinetic (muscular) energy. It was, in effect, a solar energy regime.
Plants turned a tiny proportion of incoming solar energy (less than 1%) into chemical energy via photosynthesis. People ate a tiny proportion of those plants, and ate an even tinier share of animals that also ate plants. This process captured an infinitesimal proportion of incoming solar energy, but there were few ways to improve its efficiency.
Domestication of plants and animals, which began just over 10,000 years ago, was one way. By raising easily edible plants and weeding out others, early farmers could increase their food supply and energy intake. The domestication of animals, especially those which ate plants humans could not digest, permitted yet a further expansion of the energy supply, as animal muscle power complemented human efforts.
Agrarian societies making full use of domesticated plants and animals, harvested about 4-6 times as much energy as did hunting and gathering societies, according to calculations made by Rolf-Peter Sieferle.
Water and wind power added further to the human energy supply. Sailing craft have existed for perhaps 60,000 years or more. Windmills, perhaps 2,000 years old, first came into widespread use in Persia in the 9th and 10th centuries, and in northwestern Europe in the late 12th century. Waterwheels emerged at least 2,000 years ago, and in ideal spots could deliver power in quantities otherwise unattainable.
But all the wind and water power in use as of 1800 added only very slightly to the total energy harvest, because they were practical technologies for only a few chores, such as sailing and milling grain, and because sufficiently reliable wind and water existed only in select locations.
All these energy sources tapped the tiniest share of the incoming flow of solar energy. At every turn, energy was lost: photosynthesis captured very little of the sun’s energy; human and animal metabolisms captured only about 10% of what they ate in the way of plants.
The inherent inefficiency in this solar energy regime narrowly constrained human life, ensuring that most of our ancestors had to work long and hard for meagre returns.
For heat, people could turn to stocks as well as flows of energy. Trees represented decades or centuries of accumulated photosynthesis. Wood and charcoal, helpful in heating, cooking, and a few industries such as brewing, metallurgy, or glassmaking were crucial for most human societies. But they added only to the quantity of heat energy, not mechanical energy. For that, there was no substitute for muscle.
Fossil fuels changed that. Peat, coal, oil, and gas represent gigantic stocks of fossilized solar energy, accumulated over geological time. Peat is semi-fossilised plant remains, most of which is 6-20,000 years in the making. It exists in vast amounts, mainly in high latitudes in Canada, Scandinavia, and Siberia. When dried, it makes a satisfactory fuel for some uses (not metallurgy for which its flame is not hot enough).
The Dutch are the only people to make it central to their economy, because only in Holland were large quantities of peat, a bulky fuel, available at sea level for easy shipment. During the Dutch Golden Age (c. 1560-1670), peat accounted for about half the energy used in the Netherlands.
In an age where many locations in Europe, China, and elsewhere, struggled to maintain supplies of fuel wood, peat provided the Dutch an energy-cost advantage which helped them built internationally successful brewing, sugar-refining, salt-making and other energy-intensive industries.
Peat buoyed the Dutch economy and transformed the Dutch place in the world, but coal transformed the world. Coal represents an energy subsidy from the deep geological past, frozen sunshine collected over millions of years. It carries half again as much energy per ton as does the best fuel wood, and three times as much as peat.
The first society to make significant use of coal was the Chinese during the Song Dynasty. Abundant coal in the northwest provinces helped fire an iron industry, substantially devoted to armaments production. As of the late 11th century, its size exceeded the iron industry of all Europe as late as 1700. For reasons that remain uncertain, the Chinese coal and iron industries tailed off after the 12th century.
Coal had its limitations. Most of it lay deep beneath the ground, requiring dangerous and costly work to get it out. In many lands, water collected in mineshafts, making miners’ tasks impossible. Moreover, most coal carried various impurities that made iron brittle. Coal was also heavy and therefore costly to transport.
All these limitations were overcome in Great Britain between 1700 and 1800, by virtue of technical advances, canal-digging, and the refinement of the steam engine, which could pump water out of mineshafts and thereby prevented the Industrial Revolution from drowning in its infancy.
Great Britain lay toward the northwestern end of a carboniferous crescent, the landscape stretching from the Scottish lowlands to Silesia. In 1750 this region produced less than 5 million tons of coal annually (almost all of it in Britain). By 1900 it yielded more than 400 million tons a year, about 60% of it mined in Britain.
Coal was now king, supplying the majority of Europe’s energy requirements and half of the world’s. Coal shattered the grinding constraints of the solar energy regime, opening up new opportunities hitherto not only unimaginable but genuinely impossible.
Coal was king for the span of two human generations. In 1900 primitive internal combustion engines existed that eventually would create a vast market for petroleum. Oil, liquid sunshine and another massive subsidy from the deep geological past, carries twice the energy per ton as does coal, and by virtue of its liquid form can be transported more cheaply, in pipelines and tankers. By 1960 oil accounted for more energy around the world than did coal.
Between 1800 and 2000, total worldwide energy use grew by 80-90 fold, the most revolutionary process in human history since domestication. Fossil fuels accounted for almost all the growth, and today make up about 77% of all energy use. The modern age is the age of fossil fuels.
continue to: III. Population and Urbanisation as Ecological Trends
IV. Ecological Changes
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