In the latest instalment of Age of Invention, Anton Howes considers the reasons for the rise of coal and refutes the frequently deployed “just so” story that it was driven by mass deforestation in England:

An image of coal pits in the Black Country from Griffiths’ Guide to the iron trade of Great Britain, 1873.
Image digitized by the Robarts Library of the University of Toronto via Wikimedia Commons.

It’s long bothered me as to why coal became so important in Britain. It had sat in the ground for millennia, often near the surface. Near Newcastle and Sunderland it was often even strewn out on the beaches.¹ Yet coal had largely only been used for some very specific, small-scale uses. It was fired in layers with limestone to produce lime, largely used in mortar for stone and brick buildings. And it had long been popular among blacksmiths, heating iron or steel in a forge before shaping it into weapons or tools.²

Although a few places burned coal for heating homes, this was generally only done in places where the coal was an especially pure, hard, and rock-like anthracite, such as in southern Wales and in Lowlands Scotland. Anthracite coal could even be something of a luxury fuel. It was burned in the palaces of the Scottish kings.³ But otherwise, the sulphur in the more crumbly and more common coal, like that found near Newcastle, meant that the smoke reeked, reacting with the moisture of people’s eyes to form sulphurous acid, and so making them sting and burn. The very poorest of the poor might resort to it, but the smoke from sulphurous coal fires was heavy and lingering, its soot tarnishing clothes, furnishings, and even skin, whereas a wood fire could be lit in a central open hearth, its smoke simply rising through the rafters and finding its way out through the various crevices and openings of thatched and airy homes. Coal was generally the inferior fuel.

But despite this inferiority, over the course of the late sixteenth century much of the populated eastern coast of England, including the rapidly-expanding city of London, made the switch to burning the stinking, sulphurous, low-grade coal instead of wood.

By far the most common explanation you’ll hear for this dramatic shift, much of which took place over the course of just a few decades c.1570-1600, is that under the pressures of a growing population, with people requiring ever more fuel both for industry and to heat their homes, England saw dramatic deforestation. With firewood in ever shorter supply, its price rose so high as to make coal a more attractive alternative, which despite its problems was at least cheap. This deforestation story is trotted out constantly in books, on museum displays, in conversation, on social media, and often even by experts on coal and iron. I must see or hear it at least once a week, if not more. And there is a mountain of testimonies from contemporaries to back the story up. Again and again, people in the late sixteenth and the seventeenth centuries complained that the woods were disappearing, and that wood fuel prices were on the rise.

And yet the deforestation thesis simply does not work. In fact it makes no sense at all.

Not out of the Woods Yet

This should immediately be obvious from even just a purely theoretical perspective, because wood was almost never exploited for fuel as a one-off resource. It was not like coal or peat or oil, which once dug out of the ground and burned could only be replaced by finding more. It was not a matter of cutting swathes of forest down and burning every branch, stump and root, leaving the land barren and going off in search of more. Our sixteenth-century ancestors were not like Saruman, destroying Fangorn forest for fuel. Instead, acres of forest, and even just the shrubs and trees that made up the hedges separating fields, were carefully maintained to provide a steady yield. The roots of trees were left living and intact, with the wood extracted by cutting away the trunk at the stump, or even just the branches or twigs — a process known as coppicing, and for branches pollarding — so that new trunks or branches would be able to grow back. Although some trees might be left for longer to grow into longer and thicker wood fit for timber, the underwoods were more regularly cropped.⁴

Given forests were treated as a renewable resource, claiming that they were cut down to cause the price of firewood to rise is like claiming that if energy became more expensive today, then we’d use all the water behind a hydroelectric dam and then immediately fill in the reservoir with rubble. Or it’s like claiming that rising food prices would result in farmers harvesting a crop and then immediately concreting over their fields. What actually happens is the precise opposite: when the things people make become more valuable, they tend to expand production, not destroy it. High prices would have prompted the English to rely on forests more, not to cut them down.

When London’s medieval population peaked — first in the 1290s before a devastating famine, and again in the 1340s on the eve of the Black Death — prices of wood fuel began to rise out of all proportion to other goods. But London had plenty of nearby woodland — wood is extremely bulky compared to its value, so trees typically had to be grown as close as possible to the city, or else along the banks of the Thames running through it, or along the nearby coasts. With the rising price of fuel, however, the city did not even have to look much farther afield for its wood, and nearby coastal counties even continued to export firewood across the Channel to the Low Countries (present-day Belgium and the Netherlands) and to the northern coast of France.⁵ A few industries did try to shift to coal, with lime-makers and blacksmiths substituting it for wood more than before, and with brewers and dyers seemingly giving it a try. But the stinking smoke rapidly resulted in the brewers and dyers being banned from using it, and there was certainly no shift to coal being burnt in people’s homes.⁶

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1. Ruth Goodman, The Domestic Revolution (Michael O’Mara Books, 2020), p.91

2. James A. Galloway, Derek Keene, and Margaret Murphy, “Fuelling the City: Production and Distribution of Firewood and Fuel in London’s Region, 1290-1400”, The Economic History Review 49, no. 3 (1996): pp.447–9

3. J. U. Nef, The Rise of the British Coal Industry, Vol. 1 (London: George Routledge and Sons, 1932), p.107, pp.115-8

4. Oliver Rackham, Ancient Woodland: Its History, Vegetation and Uses in England (Edward Arnold, 1980), pp.3-6 is the best and clearest summary I have seen.

5. Galloway et al.

6. John Hatcher, The History of the British Coal Industry: Volume 1: Before 1700: Towards the Age of Coal (Oxford University Press, 1993), p.25