The Natural History of the Present, Chapter 10

Chapter 10: Europe until 1800: Limits of a Fully Settled Agricultural World

Using the natural production of the forest or waste to increase the fertility of cropland is a common strategy of folk agricultures. It usually depends on domestic animals that eat leaves or grass from the surrounding uncultivated land and whose manure is then used on the fields. In a modern African variant of this system, branches from leguminous trees, grown in hedgerows between the fields, are directly used to mulch, and thus also to fertilize, crops; no animals are involved. The rapid decay rates of the tropics make this system possible.
Overexploitation of systems that depend on the surrounding forest or wasteland for a portion of their fertility is easy. While usually caused by over-population, over-exploitation can also be caused by an increase in market demand for timber, grain or fuel. An example is trekkers seeking food and shelter in Nepal. Villagers build small hotels of native lumber to take them in. They also grow more food to feed them, and more fuel to warm them, thus increasing their income at the cost of over-cutting the forest for timber, fuel and fodder. This increases erosion and the risk of landslides in steep areas. (Much of upland Nepal is steep, its slopes held in place by shrubs and trees; under traditional management, firewood was taken from dead vegetation.) The rise in the number of ski areas in Swiss mountain valleys is a more high-tech example of market-based over-exploitation of steep forestlands (which 250 years ago in the French Alps were cleared for farmland, with catastrophic erosion); now not for food or fuel but (similarly to the Nepalese) for business income. In such cases the demand for wealth magnifies the effect of population.

In the grain-and-cow culture of the Near-Eastern agriculturists who settled Europe 7000 years ago, using products of the wasteland to fertilize fields already had a long history. Fertility of upland fields is maintained on the one hand by in-situ weathering. This is the release of mineral elements from the soil by bacterial and fungal action and the erosive effect of natural rainfall, which is slightly acidic (root secretions make it more so and increase the release of minerals). Fields have much simpler plant, animal, fungal and microbial populations than forests or grasslands, and lack their nutrient cycling ability. Leaving them bare for much of the year exposes them to extensive leaching and erosion. They also have less sophisticated systems for releasing nutrients from soils. Cereal crops use nutrients equivalent to the forests or grasslands they replace, but much of their growth, along with the nutrients, is removed in the annual harvest. Nitrogen in fields is provided by free-living nitrogen-fixing bacteria in the soil, and those living in nodules on the roots of leguminous plants. The annual pulse of nitrogen may be greater in fields than in grasslands or forest, because of the warmer temperatures of the cleared ground. A good part of this nitrogen is leached out by rainfall, even from hayfields, that is, cultivated grassland. The problem is that in such simple systems, the bacterial activity that releases nutrients, and nutrient uptake by the plants, do not always coincide; then nutrients escape. For instance, bacteria may mobilize nutrients before crop plants have been seeded in the spring, or after they are done growing (or have been plowed under) in the fall. The fertility of fields depends on the balance among what is removed—by crops, by leaching, by soil erosion—and on what nutrients are produced within the field or added to it. If the soil is inherently fertile, and soil erosion is not too great, the crops not too demanding, and leaching of nutrients by rainfall remains within bounds, a field will retain a low level of fertility indefinitely. (Temperate loess soils are good here.) But the steady fall in fertility after the clearing of the natural vegetation is the reason for rotating fields back into forest. The earliest agriculturalists in Europe cultivated river floodplains with hoes (such soils were good to begin with and are renewed by floods and by soil washing down from the hillsides), but the slash-and-burn agriculturalists of upland Europe apparently moved on, with their cattle and stores of grain, when the fertility of their fields fell. Denser populations require permanent fields, however, and with the manure from domestic animals the fertility of fields can be maintained. Animals are pastured in the woods and kept nights on the fallow; fed cut branches, hay, and grain straw; and put to graze on grain stubble (where they also deposit their urine and manure). The biological productivity of uncultivated lands is a major support of such continuous grain-growing systems.

The introduction of cattle was a tremendous innovation in Neolithic agriculture. Milk provides 4 to 5 times the protein and energy for the same amount of feed as meat; cattle provide traction power; and manure for grain crops. The development of lactose tolerance in adults (the ability to digest milk usually disappears after childhood in humans) is thought to have increased the number of a person’s descendants several times (perhaps 10). In Neolithic Europe each person needed 20 hectares (48 acres) for cropland, fallowland, pasture, hay meadows, firewood, building material, and forest browse. (Branches were lopped and brought to the animals, sometimes stored in piles by the trees for the winter. This is still done in parts of the Mediterranean.) A village of 30 people needed a herd of 40 cattle, 40 sheep or goats, 13 hectares of wheat or other grain, and about 5 square kilometers of forest for firewood, timber, and animal pasture. As in Medieval times, the cropland (hoeland, plowland: the plow was invented about 6500 years ago on the Sumerian plain) was probably communal and divided into two: one field was used for winter grain, the other rested, its stubble and weeds grazed by the domestic stock, which were also kept there at night. The fallow period allowed for the build-up of nutrients from bacteria, decayed plants, and animal manure.

A variation on this system in medieval and renaissance Europe was provided by the so-called transhumance pastoralists who took their flocks of sheep up into the mountain pastures of the Alps or Pyrenees during spring and summer, returning in fall and winter to the grain-growing lowlands: Spanish wheat growers paid for the privilege of having such flocks kept on their fields for a night or a week (as long as the stubble and the roadside grass would support the animals); manuring by the sheep is thought to have doubled wheat yields. While the manure produced by the flocks came from the immediate surroundings (the wasteland, steep banks, roadside ditches, and grain stubble), the animals themselves were at least partly supported by the mountain pastures and the landscapes in between. That is, their total biomass was much greater than the local landscape would have supported. Sheep are good at converting biomass to dung, producing 10 times their weight in dung annually. So this was a way of bringing the biological productivity of the mountains to the plains and making the mountains useful to people at lower elevations. (All the same, overgrazing during the medieval period by huge flocks of sheep in La Mancha and Estremadura—those impoverished lands that produced the American conquistadores—converted large parts of central Spain to poor quality grass and scrub; and the general decline in Mediterranean forests after the Middle Ages is thought to have been caused by overgrazing by sheep.) Whether such grain-growing systems were sustainable over the long run depended on the underlying fertility of the soil (a gift of nature) and the rate of erosion (a matter of climate, soils and management), but they supported (or helped support) many of the Mediterranean and Near Eastern high civilizations.

The organized settlement systems (an early state capitalism?) of the Greeks, with their colonies in Turkey, Sicily, Egypt, the Black Sea, the Mediterranean coast of France, provided surplus grain for mainland Greece. By 400 B.C. perhaps half the food eaten in Greek cities was imported. Were such colonies a sign of erosion in Greek agricultural soils? Many Greek sites show thousand year cycles of use and abandonment. Cycles of expansion and contraction of agriculture and population during the Neolithic and Bronze ages occurred throughout the Mediterranean basin and central and western Europe, especially on upland sites. As people filled the better soils of the river valleys and lower slopes, the population continued moving up to the poorer soils of the surrounding hills. Such settlement was followed by massive erosion (visible in cores from lakes or swamps), followed by the abandonment of land, depopulation, the regrowth of scrub or forest, until some centuries later, when the soils had rebuilt themselves, settlement began again. Many European and Mediterranean landscapes were thus deforested and cleared several times over 7000 years. Such cycles continued into the classical and medieval periods.

Greek colonies were followed by those of Rome, the citizens of whose capital were entitled to a daily ration of grain, and whose grain-shed included most of the Mediterranean basin. Egypt was called the granary of Rome; there were also the more or less new lands along the North African littoral, in Turkey, and in southern France. Under a law of 111 B.C., any Roman citizen could claim up to 20 acres of public land to cultivate; by bringing it under cultivation he established ownership. This was 10 times the size of the individual holdings Romulus passed out during the settlement of Rome 600 years before, an indication either that agriculture had become more commercial or soils had become less productive. In 750 BC a man with a hoe could cultivate two acres of olives, grapes, vegetables, cereals, and fodder crops. The multistory canopy saved labor, prevented erosion and took half the land to feed the same number of people as plowing with an ox; but for large landlords plowing with an ox was more profitable. At any rate cultivation in Italy expanded; the land near Rome, once full of orchards, became large grain-growing estates, and then, as the soil declined or eroded away, uncultivated wasteland. Wood use in Rome has been estimated at 1 to 1.5 cubic meters per person per year, in total about the wood in 30 square kilometers of forest. Is such a number high or low? Per capita wood use in North America before the Revolution was 17 cubic meters a year, about 4.5 full cords, that is 11 to 17 times as much. (Two hundred years later modern people in the northeastern United States use 4 to 5 cords per winter to heat their houses; less than 1 cord if their houses are super-insulated.) Deforestation for metal smelting, pottery-making, brick and lime burning, building material, for new agricultural land, for pastureland, meant the continuous exposure of bare and overgrazed soils to the elements; and led to slow, massive, cumulative soil erosion. Composting, crop rotation, and the use of manures in maintaining soil fertility were known to the Romans (and probably to earlier peoples: the slow charring of vegetation, along with composting, began producing black earth soils in the Amazon Basin 2500 years ago), but such practices were not widely followed, and soil exhaustion and erosion imposed long cycles of settlement, abandonment, and re-settlement on river valleys throughout the Mediterranean, and influenced the larger empires of which they were a part (thus, the colonies, the importation of grain). Many former Greek and Roman port cities now lie several kilometers from the ocean. Some of this erosion would have occurred without human intervention, as the Mediterranean climate became drier, and the landscape more susceptible to erosion from its intense rainstorms, but human manipulation of the landscape speeded things up. Some Mediterranean uplands have little soil left to erode. The vine and olive, with winter wheat on flat ground, the tree fruits that date from Roman times (many brought from Persia), and the sheep pastured on the aromatic but not very palatable herbs of the once forested mountains of Crete or Lebanon constitute the modern and beautiful Mediterranean landscape. Springs and streams dry up in summer; the total run-off from the landscape is greater. On hilly land near Rome, farmers plant hazelnuts by blasting small holes in the light volcanic rock, then plant the shrubs, and water them until they take or die. Those that die (perhaps half of the first planting) are replanted. No natural topsoil is left. Such persistance constitutes land rehabilitation: the re-creation of soil with dynamite, tree roots, tree litter, hope, and hard labor.

The agricultural remaking of Europe has left various signs, some of which we can read. Pollen cores from English ponds show pollen of oaks replaced by that of weeds, wheat, rye, hazel and birch. Hazel and birch are early successional species; hazel was often coppiced for fuelwood, that is, cut at short intervals from stands that sprout from stumps. Agriculture, by baring and stirring the soil, mobilizes the soil’s lead in airborn dust. Airborn lead from Roman silver smelting shows up in cores from the Greenland icecap. Cores from peat bogs in the Jura Mountains of France show variations in airborn lead in the surrounding landscape over the last several thousand years. An initial rise 8000 years ago corresponds with a volcanic eruption in France. Soon afterward Neolithic agricultural activity tripled the relatively constant, post-glacial background level. A further rise in lead 3000 years ago corresponds with smelting at Phoenician lead mines in Spain. There were rises corresponding with Roman and Greek metallurgical activity (a layer of lead from Roman silver smelting is found in lake muds all over Europe), a decline from those heights in the Middle Ages, and a rise with the Industrial Revolution that peaked in 1905, the rise in this case caused by coal burning as well as metal smelting. Total airborn lead peaked again in 1967, from lead in gasoline, on top of all the other sources, when it reached 85 parts per million. The post-glacial background concentration was 0.28 parts per million. So anthropogenic lead in the modern atmosphere is something like 250 to 300 times that of the hunting and gathering background, that to which one assumes modern people and animals are adapted.

The two-field system helped support Greece and Rome. The fields, fallow or cropland, were plowed in spring, summer and fall (they were planted in the fall). Together with Egypt’s Nile Valley, and some irrigated lands, the two-field system supported the Islamic civilizations of Turkey, the Middle East, and North Africa. (“Some irrigated lands” includes lands watered by qanats, underground tunnels that collect groundwater from mountain slopes. Qanats are found in the Middle East, Cyprus, Iran, Central Asia, and in parts of North Africa. Their design makes them self-regulating, though they must effect surface waters. Their flow in Iran in 1960, to provide urban water and to irrigate farmland, has been estimated at that of 12 Nile Rivers. For the most part qanats have been replaced by pumps, that is, water taken from deep wells and rivers, but the cities of Bam and Irbil still use water from qanats dug by the slaves of Sennacherib 2700 years ago.) The two-field system supported the civilization that followed Rome in Europe north of the Alps: its surpluses (wheat yielded only twice the seed sown) built Romanesque churches, fortified castles, early walled towns. About 800 A.D., when Charlemagne was crowned king of a united Europe in Aachen, a three-field system had come into use in some villages in northeastern France. The common ploughland was divided in three parts. One field was planted in autumn with a winter grain (wheat or rye); this is the traditional method of Mediterranean or Near-Eastern agriculture that had been brought to Europe several thousand years ago. Another field was planted in spring with a summer crop of oats, barley or peas (the last a nitrogen-fixing legume); this was new. The third section was left fallow. This system increased total crop yields, putting two-thirds of the plowland into crops yearly. It increased the land in crops by a sixth. It also increased crop variety, provided more fodder for the animals and spread work more evenly over the year. More fodder meant more manure and greater yields, a positive feedback. In later centuries a winter fodder crop, often turnips, would be planted for the animals.

The re-settlement of Europe that followed the crowning of Charlemagne was intended to remake the European landscape into a holy and cultivated earth. Charlemagne renamed the months (then, as now, named for Roman gods and goddesses) for their agricultural activities (the month to plow, the month to plant, the month to cut wood). Around 1000, the wheeled iron plow, pulled by a yoke of 8 oxen, came into common use. This implement, invented several centuries earlier, made possible the conversion of Europe’s heavier soils (the clays on which the oaks grew) to agriculture. The invention of the shoulder harness and the nailed horseshoe led to the growing use of the horse for traction power. Horses are several times more expensive to maintain than oxen and must be shod to protect their hooves from the northern European damp, but can exert more force and work faster for a longer time. Such developments in agriculture opened up new lands in Europe and by 1100 led to prosperity across the continent from the Atlantic to the Dnieper. The 1100s brought the first European manufacturing age, powered by wind and water mills. Europe had abundant resources of wood, flowing water and minerals. Water mills were used to mill grain, full cloth, process hemp, for tanning, laundering, milling logs, crushing and grinding ores, sieving, turning, polishing, stamping, for iron-making (operating bellows, puddling and beating iron, drawing wire). Watermills averaged one per 50 families in England.

So the Dark and Middle Ages that followed the death of Charlemagne were a time of boom: in population, in land clearance (sometimes of land abandoned after the collapse of Rome), iron manufacture, stock raising, the founding of new towns. Fields were 5% of Europe in the sixth century, 30-40% in the later Middle Ages. Religious orders established monasteries in the wilderness and granted colonists their forestland to clear and cultivate. Interested in increasing their income, the nobility also established colonizing settlements and began the reclamation of marshland and heath. Forest cover in Europe was reduced from 80% (95% originally) in 500AD to 50% or less in 1300. (Some writers claim only 20% of the forest was left by 1400, that in France perhaps 25% of the forest remained.) That forest was heavily exploited for fuel and timber. Land use had fallen to 2 hectares per capita from 16 to 20 in Neolithic times. The climate was also good. During the so-called Medieval Climate Optimum (from about 1000 A.D. to 1400 A.D.; some writers now put it a century earlier) temperatures in Europe were about 1º C. warmer. This lengthened the growing season by a month. The climate change was worldwide. The warm period in Europe coincided with a warm period in the Arctic (southwestern Greenland was settled by the Norse and grain was grown in Iceland), while most of the earth was slightly cooler and civilizations in Central America, the Andes, and the American Southwest collapsed from droughts.

Population in Europe doubled from 1000 to 1220, from 38.5 million to 75.5 million; from a base of 18 million in 600. New land was gone by 1300, and the population was reaching the limits of its renewable resources. Overall yields fell as more and more marginal lands were brought into cultivation; wages fell. By 1300 Europe’s expanding population had overwhelmed its productive capacities. Trade was still a small part of the economy, which was largely agricultural. Roads were poor and travel unsafe. Religious views discouraged much economic activity (for instance, lending money at interest—usury—was a sin). Land in the medieval economy was held by right of occupation and was difficult to sell. Labor could be hired but was governed by a customary web of rights and obligations. Many of the so-called prerequisites for economic growth did not exist. These include secure property rights, the rule of law, more or less working markets, some social mobility, a desire by the individual for financial improvement. The Hundred Year’s War, a general European war, began in 1337. Catastrophe arrived 11 years later as a plague. The plague turned out to be a blessing in disguise.

Europe in 1300 still depended on renewable resources. The primary limit was food. Production per acre would rise 2.5 times during the succeeding centuries, with better forage crops and legumes, animal breeding (which produced more milk or flesh from the same amount of feed), more complex rotations, new crops and animals from Asia, Africa, India and the Americas; but yields never kept up with population, and periodic starvation in Europe continued until the Industrial Revolution. Death from famine and cold were common in Europe in the 1700s. Many episodes of starvation were local, a matter of food distribution rather than absolute shortage (as is still the case in Africa now). The last famine in Europe caused by an absolute shortage of food was in the early 1800s, when the eruption of Krakakoa in Indonesia injected enough dust into the stratosphere to cause two years of climate cooling worldwide. In New England in the year following the eruption, frost occurred in every month. The Irish potato famine, which followed this, was not caused by an absolute shortage of food (Ireland exported food throughout the famine), but by the failure of the British government to distribute food to a starving population. The Irish famine was an unexpected problem of industrialization: that of the introduction of new organisms to new environments. The blight that destroyed the potato crop was brought to Belgium on American seed potatoes imported by steam ship. The rapidity of the trip across the Atlantic allowed the fungus to arrive on the potatoes alive, and the damp summer that followed allowed it to spread all over northern Europe.

Another renewable limit was fuel. Until the 1700s (earlier in England) wood was the primary fuel used for industries and crafts, as well as for cooking and heating. Brick burning, glassmaking, iron smelting, salt evaporation, lime burning, sugar refining, soap making, brewing all required fuel. Heating and cooking probably required the most. Shortages made wood expensive; in 1600 the average city dweller in France spent 10% of his income to keep a fire burning in one room for part of the day. In general, from 1500 to 1700, 7.5% of an ordinary budget went for light and heat. (More efficient brick or stone heating stoves in central and northeastern Europe made it more comfortable in 1700 to winter in Warsaw than Toulouse.) Timber was necessary for buildings, tools, ships and furniture. Hazel and oak, species that sprout well from stumps, were cut on short-term rotations to provide fuel and also materials like tanbark. Some oak stems (the standards) were allowed to mature for timber. But supplies were limited to what forest growth provided. In the European wars of the eighteenth century, English blast furnaces, needed to forge cannon shot, could only operate intermittently; when they ran out of charcoal, they had to shut down. (Eight tons of wood made two tons of charcoal, which would smelt just under a ton of pig iron.) Similar shortages occurred all over Europe. Since iron making depended on a renewable resource, production of iron had to remain at or below what the wood supply could handle. If production were increased to meet an increase in demand, the supply of wood in the future would be reduced. Future production of iron would have to be lowered, or stopped altogether. Everything depended on the growth of the trees, which put an inexorable limit on production. Where available, coal could be used for cooking, heating, and processes such as brewing that simply required a source of heat. Coal was commonly used for such purposes in England, where wood shortages developed early and coal was abundant. Coal had largely replaced wood for household heating and cooking in England by 1700. The adaptation of essentially unlimited European coal supplies to iron smelting was a fundamental factor in the rise of the Industrial Revolution.

There were other problems related to an overexploitation of a renewable environment. One of the more serious was soil erosion. This reduced soil fertility (nutrients were lost with the soil and the depth of topsoil was also reduced); caused the siltation of streams, which increased flooding; and ruined freshwater fisheries. (The gravels in which the fish laid their eggs silted over. Mill dams also destroyed fisheries. Riverine fisheries were failing in Europe by 1000 and were replaced by the cultivation of fish in ponds — many fishponds in the 1100s and 1200s were the dammed sections of rivers and streams, but with different species of fish.) Eroded soil also filled waterways and harbors. Harborworks of cities in the Rhine delta suffered. Bruges in present-day Belgium, the commercial center of northern Europe in the 1300s, watched its harbor on the Zwin disappear, silted past the ability of the city to clear it. Rivers were also polluted by metal works, dye works, tanneries and sewage. Wells were polluted with seepage from cesspits and from rotting bodies in churchyards. The smell of cellars about the cemetery of Les Innocents in Paris was notorious.

Overfishing followed population growth, as marine fish began to replace freshwater fish in the European diet; the trawl was invented in the 1300s, with disastrous effects on fish stocks and the life of the seafloor. With the trawl, cod off the English coast became so easy to catch that the surplus was fed to pigs. Diking to reclaim land in the Rhine Delta caused major losses in sturgeon, once a key item in the European diet, by destroying its spawning habitat. By 1500 stocks of herring in the Baltic and of cod in the seas about Europe were failing. (Except for the Danish herring fishery, which collapsed with finality in the 1300s, the cod and herring fisheries would recover to fail again.) The Baltic and North Sea herring fisheries originally amounted to billions of fish annually. Fish was one of the sources of wealth of the cities of the Hanseatic League. (Even in the late 1600s, work in the herring fishery constituted 20% of the Dutch economy.) In the late 1400s fishermen from Bristol sailing west of Iceland discovered the Newfoundland cod fisheries. Did they stop to take on some of the Norse colonists in southern Greenland, whose culture was failing? By 1600, 20,000 European fishermen were salting and drying cod off Newfoundland. Dried cod from the North American banks would provide a cheap source of protein for Europe for 500 years.

Until the Industrial Revolution, the European world was Malthusian. That is, its population tended to increase faster than its food supply. In a downward spiral, more people meant more demand for grain, less crop rotation, less fodder for the animals, not enough manure to raise grain yields, the animals dying from parasites and malnutrition in late winter and spring. People died from hunger and exposure. Infant mortality was 25-30% until the late eighteenth century, life expectancy was 30 to 40 years, epidemics were common, most of the population was undernourished and depended on vegetable foods (bread, gruel, potatoes). Much of the population was very poor. At the time of the French Revolution, 80% of the population of France is thought to have been poor or destitute; that is, they owned the clothes on their backs. Many were more or less homeless, not being able to afford both food and lodging. In Medieval and Early Modern Europe four-fifths of disposable income went for food. The nobles and the members of the middle-class ate well. These distinctions lasted in England long into the period of industrialization: in 1800, boys taken into the Royal Navy from the slums of London or Liverpool were 8 inches shorter than boys from the upper classes; in 1940, working class draftees were still 4 inches shorter than boys who had gone to elite schools. So one could recognize an officer by his stature. Until about 1700, periods of growth in the standard of living of the common people were followed by periods of reversal (the long waves in the economy were cyclical), so the standard of living of an agricultural worker in Europe in 1500 or 1600 was only slightly higher than in Roman times. When Europeans came to North America, where food was plentiful, their numbers, instead of doubling every 150 years, began to double every 23 years. (Most of the first-born children in Puritan families were illegitimate.)

This is not a portrait that leads to a progressive view of history (constant progess onward and upward). That view would come out of the cascading improvements in material life with the Industrial Revolution (railroads, steam power, gas lights) and their consolidation and elaboration in the twentieth century (electricity, cars, radio, penicillin, TV). In the United States, more egalitarian and less bound by social traditions than Europe, especially after the Civil War, markets expanded with the population and economic productivity grew at 2% a year from 1870 to 1970. (In general, a more widespread prosperity increases the rate of economic growth.) But it is also not the whole picture. From 1200 to 1800, during a period of worsening climate, agricultural yields in Europe rose 2.5 times, while population rose 10 times. Land under cultivation increased several fold. During the so-called Little Ice Age, from 1430 until 1850, the climate was 1º - 2º C. lower than during the Medieval Optimum. A severe famine from 1315 to 1322 may have set the stage for the Black Death of the 1340s and 1350s (fetal malnutrition interferes with the development of the immune system) and killed outright perhaps 10-15% of the population. The Black Death killed a third to a half of the population. Recurrent epidemics followed for the next century and there was another famine in the 1430s. For the most part crops near their natural temperature limits (at high altitudes or latitudes) failed. During the Little Ice Age cereals could no longer be grown on the hills of northern and western Britain, glaciers and the tree line descended in the Alps, and the northern limits of vinyards in France and Germany retreated 300 kilometers south. Yields of grain on newly cleared land during the warm summers of the Optimum had been twice those of late Roman times but inevitably fell as soils eroded and fell further as the weather worsened. Most of the cooling took place in winter (this was a time of ice-skating and ice festivals) but summers were also 0.8º C. cooler.

After the calamitous 1300s, with disease, famine and continual low level war, came a period of recovery. Europeans rebuilt their water mills for water-powered industry. Tenants gained heritable rights to their land in return for rents. Some common lands began to be enclosed to create rentable tracts. (In the late 1500s, it was said a living was three acres and a cow. People were still saying that in upstate New York in 1850.) Towns, supported by agricultural surpluses, grew into small industrial centers. Industry in late medieval Europe was for the most part cloth, of wool or linen, woven on hand looms at home. By establishing chartered political units, surrounding themselves with walls, and mobilising their citizens into a defensive force, towns established a degree of political independence, both from the church (many towns were founded as the seats of bishops) and from the countryside and the nobility that ruled it. Intellectual life bloomed as paper replaced skin parchment in books (paper was 13 times cheaper than parchment at the time) and printing (also much cheaper) replaced hand copying. Books became more affordable; before the printing press, a professional man’s annual salary bought two cows or four books (and nothing else). After the printing press, a middle class person could afford a couple of books a year. As land became more valuable, property rights became more exclusive, and began to extinguish the traditional rights of the nobility, such as that to ride or hunt where they pleased, and those of the peasantry, which included the right to common grazing land and to fuelwood gathered from the forest. Trade spread once again (memories lingered of the fairs of the 1300s), its bankers and merchants operating under the protection of the towns. Some of this trade was for commodities like Baltic timber and grain and some for luxury products like the silks and spices of Asia, to which the caravan routes, closed for some centuries by drought and the expansion of Islam, were once more open. Imitating the nobility, families of the middle class tried to keep their wealth through such devices as late marriage (thus limiting their fertility); by advantageous marriages between families; or by restricting inheritance to first-born sons. A writer has said that among the wealthy, population control was positive, while among the poor, population was controlled by starvation. In Paris at the time of the Revolution one-quarter of all children are thought to have been abandoned for adoption. Such infants were taken in by church orphanages, where the great majority of them died.

The medieval boom had ended with the famine of 1315 to 1322. Every season of 1315 was wet. Crop yields were half of normal. Hay was put up wet and rotted in the barns. During the winter and spring of 1316 people ate their seed grain. The year 1316 continued wet with another crop failure. The price of wheat tripled, when it could be bought. The famine continued until 1322. Twenty-five years later, after several warm, wet springs favorable to the spread of plague among the rodents of Central Asia, the Black Death arrived with people on ships from trading posts on the Black Sea fleeing the Mongol invasion and killed a third or more of the population of Europe. Parts of Europe would not see the population reached during the Climate Optimum for another 450 years. But the decline in population was followed by a period of development and prosperity: the Renaissance. The average age of death for adults was still something like 35. Still hemmed in by the Islamic world, Europe began probing its limits. Genoese bankers (who had financed the trading cities on the Black Sea) now financed Portuguese explorations around Africa to the Spice Islands of the East and out into the Atlantic, where large semi-tropical islands were discovered. New crops had been appearing in Europe thanks to trade with Asia and contact with the Moors in Spain; these included rice and sugar cane and the new livestock of silkworms. After 1492 came American crops. The yields of Mexican corn and Andean potatoes would dwarf those of European grains. A writer has speculated that the introduction of maize, peanuts and manioc from the Americas to Africa, which substantially increased the human population there, made the trans-Atlantic slave trade possible. New diseases (such as yellow fever) came with trade and with the Africans to Europe and the New World.

The high point of European row-crop agriculture was reached in England in the eighteenth and nineteenth centuries. The development of rotations between cereals and crops of legume hays (which raised the yield of grain per acre), the raising of animals on legume hays (which increased the numbers of animals that could be kept), and the use of animal manures on the fields (which further raised the yields of grain), together with plant and animal breeding that resulted in higher yielding varieties of plants and animals (more meat, wool, or grain for the same nutritional input) — all raised European upland agriculture toward the heights of successful overflow agriculture (such as in the Nile Delta), the ditched fields of Tiahuanaco, or paddy rice. That is, it became a high-yielding, self-sustaining agricultural system, less dependent on inputs from the wasteland, capable of supporting many more people per acre. Enclosure laws in England, enacted partly to ensure an adequate supply of manure for cropland (the relation of pastureland to cropland is important in manure-dependent cropping systems), better equipment, and better capitalized farms put many agricultural laborers and small tenant farmers out of work; some went to poorhouses, some to Australia or the Americas, some to work in the shops of the Industrial Revolution. Agricultural prosperity showed in that in the 1800s horses replaced oxen in Europe as the main source of agricultural power. (Horses are able to work faster for a longer time but are several times more expensive to maintain.) Environmentally speaking, such mixed agricultures were a high point of upland agriculture; they were sustainable as long as they occupied a more or less limited place in the larger ecosystem. Similar agricultures flourished briefly on the American prairies, and in the German settlements of the Shenandoah Valley of Pennsylvania and Virginia. One finds them still among the American Amish.

What ended the European dependence on the renewable world was the use of fossil fuels. England was the European nation most short of wood. It was largely deforested, probably not for the first time, when the Domesday Book was compiled in 1089 AD. (For instance, deforestation of the English downlands had begun in Neolithic times 5500 years before and had continued through the Roman invasion of AD 43. Deforestation, erosion and grazing converted the original downland woodland of oak, alder, willow, hazel, birch and rowan into the thin-soiled grasslands of today.) England was also the country most in need of wood for its imperial ambitions and it was here the Industrial Revolution began. (While some developments came from the continent, the English most thoroughly exploited their economic possibilities, probably thanks to their better developed markets.) A writer has summarized the reasons for the development of the Industrial Revolution in Britain: the greater size and efficiency of British markets (many of the export markets created and maintained by Britain’s sea power); Britain’s commercially minded society; Britain’s openness to innovation; and its accumulation of natural resources from around the globe (also a function of its sea power). In the late eighteenth century machines were developed that, powered by water, would spin cotton thread; other machines wove the thread into cloth. The mechanical advantage of the machinery was so great, the multiplication of the value of the labor and investment so enormous, that the major limits on cloth manufacture became the availability of waterpower, of raw cotton, and of the ability to market the cloth. The manufacturing process was so cheap, compared to hand spinning and weaving, that the manufacturers were able to lower the price until demand met supply. Once cloth fell within reach of the poor, an enormous market was created and demand exploded. Profits were still enormous. The invention of the cotton gin, which mechanically cleaned cotton (previously slaves had picked out the seeds by hand) had a similar advantage: one didn’t just double or triple the value of labor, one increased it by orders of magnitude, powers of ten. During the 1780s, as the English were losing their American colonies, industrial growth in England rose from 1% to 4% a year. It remained near 4% (some writers claim 2%) for a century.

It was the use of fossil fuels to smelt iron ore and power steam engines that finally changed everything. In England in the late eighteenth century processed coal (coke), rather than wood, was first used successfully to smelt iron ore. Unprocessed coal had too many impurities compared with charcoal and the iron smelted with it was too brittle. The coke-making process eliminated these. Coke was much cheaper than charcoal. And coal to make it was available for the mining, as was iron ore. Coal fired the steam engines, made of coke-smelted iron, that pumped the water from English mines and let the miners produce more coal. Coal-powered locomotives, built of iron and running on iron rails, hauled coal and iron ore to where they were needed. Coal-powered spinning machines took over from water-powered ones, removing another constraint from the manufacture of cotton. Coal was later joined by oil and natural gas, useful because they were fluids rather than solids, and so flow under gravity or pressure. Such fossil fuels became unlimited sources of energy in an otherwise renewable and limited world. Fossil fuels will likely remain available for a long time. (For coal the current guess is another 200 to 400 years.)

Coal-powered steam engines eliminated the limits set by floods or frozen waterways in water transportation, by replacing canal and river traffic with rail. In the 1860s coal-powered steamships, built of coal-tempered steel, carried three times the cargo twice as fast as sail. With transportation faster and cheaper, Europe reached out to the rest of the world for its resources. From 1860 to 1920 one billion acres of new land was converted to agriculture, 40% in the United States (much of it in the Corn Belt), 20% in the Russian Black Earths, 20% in Asia. Grain was imported from the “new lands” in the Ukraine, North and South America, and Australia. (Land clearing would continue, with another billion acres added to agricultural lands from 1920 to 1980, mostly in Latin America.) Refrigeration and pasteurization of milk made milk more saleable and its production rose enormously, with beneficial effects on the European diet. Milk now constitutes 20% of the value of agricultural production in Europe and the United States. Imported fertilisers such as rock phosphate and Peruvian guano increased the fertility of European soils. But it was primarily cheap imported food, its cheapness made possible by the exploitation of fossil fuels, that ended starvation in Europe. The pre-industrial European diet in 1800 was worse than that of the European hunter-gatherers of 12,000 years before. The diet worsened further during the early years of industrialization (the average height of men in both America and Europe fell in the 1830s) but improved after about three generations of industrialization. (By the 1920s the shortfall in height was gone.) By 1900 England was importing 80% of its grain, 75% of its dairy products, and 50% of its meat.

Coal also made the chemical industry possible. Coal provided the energy to run the reactions; while coal, oil and natural gas replaced wood as a feedstock. The Haber process, which synthesizes ammonia from atmospheric nitrogen, led to the manufacture of synthetic nitrogen fertiliser, which further increased the yield of soils. Artificial fertilisers and further developments in crops and animals would make Europe nearly self-sufficient in food by the mid-twentieth century. However the excess nitrogen used on crops would cause tremendous pollution problems. Anthropogenic nitrogen lies behind the biological degradation of marine estuaries and (along with phosphorus) of fresh waters. Nitrate pollution in the Thames and Rhine are now two orders of magnitude (100 times) above the mean values of unpolluted streams. (Not all of this is due to agriculture; some nitrogen and phosphorus come from sewage effluent and some nitrogen from the combustion of fossil fuels.)

By the end of the nineteenth century coal was being used to generate electricity. By two decades into the twentieth century coal and oil had produced the modern world, where the problem is not that of producing enough, but of creating demand for all that can be produced. Through gaslight and electricity, fossil fuels had eliminated night. They ameliorated the seasons through heating in cold climates, cooling in hot ones. Fast, cheap transportation eliminated the agricultural seasons, so that now any modern expects fresh fish, fresh lettuce and fresh grapes to be available anytime, whenever he or she wants them. The human habitat in developed countries, even in rural areas, is almost entirely a built one, of roads, telephones, powerlines, fields, houses, internet communication. The cost of food has kept falling until it is now less than 10% of income in developed countries. Such development comes at a cost. In 1850 every Englishman used the equivalent of 1.7 tons of coal a year; this rose to 4 tons by 1919, where it remained until 1950, despite considerable economic growth, when the number began rising once again. Such energy use brings us other problems. But the notion of man’s independence from nature and its constraints is a hallmark of the modern.