Energy, population, and environmental change since 1750: entering the Anthropocene

J. R. MCNEILL

Introduction: slouching towards the Anthropocene

And what rough beast, its hour come round at last,

Slouches towards Bethlehem to be born?

- W. B. Yeats, “The Second Coming”

Lately a host of scholars, scientists, journalists, and others have begun to bandy about the term “the Anthropocene," a term popularized by the atmos­pheric chemist Paul Crutzen since 2000.¹ By that they mean, roughly, the age in which humankind has exerted a significant/large/dominant impact on the Earth's environment.

Geologists, who claim sovereignty over the periodization of Earth history, are struggling vainly to create a common definition of the term to match definitions they accept for other eras, epochs, and periods such as the Miocene or the Holocene. One of their usual requirements is what they call synchron­icity: the Anthropocene, to be legitimate in their eyes, must begin at the same time everywhere. Further, most geologists require a “golden spike,” a datable marker in the strata of the Earth itself that shows the beginning of any epoch or era. One candidate for this honor is the layer of radioactive fallout that accumulated between the first atomic test at Alamogordo in July 1945 and the ban on atmospheric nuclear testing in 1963.

For the purposes of this chapter, in which the customs of historians are observed over those of geologists, the Anthropocene began at different times in different places. Some places, for example Venice or Mexico City, were well into their local Anthropocenes by 1750. People had transformed swamps into cities in both places. Other places, such as the peaks of Patagonia or the depths of the Marianas Trench, which are (I imagine) very much as they were in recent centuries, may not have entered it yet.^[45] So in some respects, the Earth had already entered the Anthropocene by 1750, indeed well before. But in others, it has not entered it yet. That would not suit most geologists, but it should be acceptable to historians. Throughout the period treated in this chapter, 1750 to the present, people and their planet as a whole have been entering the Anthropocene - at first slouching towards it at a stately pace, later zooming faster and faster. Increasingly, human impact on the Earth occurred on global as well as local scales.

Within this epoch, it is sensible to see two different periods. The first extended from c. 1750 until c. 1950 and was the age of coal and of (nearly) i percent per annum population growth. The second, from c. 1950 until the present, is the age of oil and of (nearly) 2 percent per annum demographic growth. The first period was turbulent enough; the second tumultuous.

Energy and industry

Several big shifts took place to nudge us into the Anthropocene, but the biggest of all was the adoption of fossil fuels and the leaps in energy use since 1750. The acquisition of fire and language made our ancestors fully human. The adoption of agriculture laid the basis for cities, civilizations, and states. The adoption of fossil fuels made us modern. Each of these marked a great shift in the human condition, in the sense that each encouraged greater complexity in human society and in the human relationship with the Earth.

Our hunting and foraging ancestors lived in a solar energy regime. Plants turned a tiny proportion of incoming solar energy (less than 1 percent) 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. Their bodies converted to heat and mechanical or kinetic (muscular) energy some of the chemical energy in their food. This process captured an infinitesimal proportion of incoming solar energy, permitting our ancestors an energy harvest of less than 2 percent, per capita, of what twenty-first-century people (on average) enjoy.

Domestication of plants and animals, which began a bit more than 10,000 years ago, increased that harvest. Agrarian societies making full use of domesticated plants and animals, harvested about four to six times as much energy as did hunting and foraging societies. Eventually, water and wind power augmented the human energy supply. But all the wind and water power in use as of 1750 added only very slightly to the total energy harvest, because they were practical technologies for only a few tasks, and because sufficiently reliable wind and water existed only in select locations.

After 1750, fossil fuels began to corrode these constraints. Peat, coal, oil, and gas represent gigantic stocks of fossilized solar energy, accumulated over about 500 million years. Peat is semi-fossilized plant remains, most of which took 6,000-20,000 years in the making. 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 fuelwood, peat provided the Dutch an energy-cost advantage which helped them forge internationally competitive brewing, sugar-refining, salt-making, and other energy-intensive industries.

Peat transformed the Dutch place in the world, but coal transformed the world. Coal amounts to frozen sunshine collected over hundreds of millions of years. It carries half again as much energy per ton as does the best fuelwood, 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, which as of the late eleventh century, 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 twelfth century.

Coal had its own 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 nearly impossible. Moreover, most coal, though it burned hot enough for metallurgy, carried various impurities that made iron brittle.

Great Britain lay toward the northwestern end of a carboniferous crescent, the landscape stretching from Silesia to the Scottish lowlands - even more crucial to the industrial age than was the fertile crescent to the agrarian age. 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

added only to the quantity of heat energy, not mechanical energy. For that, there was no substitute for muscle.

60 percent of it mined in Britain. Coal was now king, supplying the majority of Europe's energy requirements and half of the world's. Where it was used in bulk, coal shattered the grinding constraints of the solar energy regime - something peat could never do - opening new opportunities hitherto both unimaginable and genuinely unattainable.

Coal was king for the span of two human generations. By 1900, primitive internal combustion engines existed that eventually would create a vast market for petroleum (Fig. 2.1). Oil, in effect concentrated liquid sunshine, carries twice the energy per ton as does coal. Pipelines and tankers can transport it more cheaply than anything can carry coal. By i960 oil accounted for more energy use around the world than did coal. Oil can do just about anything coal can do, and a few other things - such as power aircraft - besides. After a co-regency with coal in the middle of the twentieth century, oil has remained king to this day - another two human generations so far.

Between 1750 and 2015, total worldwide energy use grew by 90-100-fold, the most revolutionary process in human history since domestication. By about 1870 humans used more fossil fuel energy each year than the annual global production from all photosynthesis.

Within the Anthropocene, the last several decades amount to an energy orgy. Our species probably used more energy since 1920 than in all of prior human history. Between 1945 and 2015, we burned around 50 million to 150 million years' worth of fossil sunshine. Plenty more remains, mostly coal.

Global averages and totals of course conceal sharp differences. In 1960, most of the world outside of Europe and North America still used little fossil energy. The energy-intensive way of life extended to perhaps one-fifth of the world's population. But late in the twentieth century that pattern, in place since 1880 or so, changed quickly. In the forty-five years after 1965, China increased its energy use by twelve times, India by nine, Egypt by nine or ten. Meanwhile US energy use rose by about 40 percent. The United States accounted for a third of the world's energy consumption in 1965, but only a fifth in 2009; China accounted for only 5 percent in 1965, but a fifth in 2009, and in 2010 surpassed the United States to become the world's largest energy user.

In sum, the burgeoning rate of energy use in modern history makes our time wildly different from anything in the human past. The fact that for about a century after 1850 high energy use was confined to Europe and North America, and eventually - if to a lesser extent - to Japan, is the single most important reason behind the political and economic dominance these regions

Fig. 2. i A derrick in the early days of Persian oil field development in 1909 (© Hulton-Deutsch Collection/Corbis)

enjoyed in the international system. Since 1965 the total use of energy has continued to climb at only slightly diminished rates, but the great majority of the expansion has taken place outside of Europe and America, mainly in East Asia (Tables 2.1 and 2.2).

Table 2.1 Globalcoalproduction

Sources: Rounded from the HYDE database; BP

Statistical Review of World Energy (2013)

Table 2.2 Global oil production

Sources: Rounded from the HYDE database; BP

Statistical Review of World Energy (2013)

Abundant and cheap energy stretched the ecological reach of humankind. Beyond the obvious environmental implications of mining, transporting, and burning fossil fuels - alone a major disruption - cheap energy encouraged industrialization as never before.^[47] Industrial economies required raw materi­als in quantities far exceeding those needed for artisanal production, much of which came from plantations scattered around the globe.

Plantations had existed for millennia, and during the sixteenth to eight­eenth centuries had become the standard means by which to produce sundry commercial crops. After 1840, steam-powered machinery could transform cotton into clothing very cheaply, inspiring a cotton frontier at the expense of forest in the American South, and new efforts to raise cotton in India, Egypt, the Anglo-Egyptian Sudan, French Polynesia, and scattered locations in Central Asia, Southeast Asia, and Latin America.

But cotton was only part of a new plantation complex that industrialization created. Tea, coffee, tobacco, jute, palm oil, copra, and various other stimulants, lubricants, foods, and fibers made the industrial revolution hum as smoothly as it did. Most new plantations were carved out of former forest lands, often as a form of shifting cultivation, because the crops and production methods wore out soils quickly. Tobacco, cotton, and coffee, in particular, depleted soil nutrients rapidly, and absent expensive conservation measures required new soils, enriched by the ash of freshly burned forests, in order to be economic. Keeping the growing populations of the new industrial cities fed, clothed, and caffeinated led armies of slaves in Alabama, Cuba, and Brazil, and legions of laborers elsewhere, to burn off millions of hectares of old-growth forest (Fig. 2.2).

Food and fiber frontiers formed only a part of the impact on the land in the age of fossil fuels. Cheap transport - railways and steamships - made mining ores in remote locations more practical. Industrial cities could buy (except during economic depressions) all the copper, tin, iron, bauxite and other ores that Chile, Malaysia, Australia, Siberia, and Jamaica could yield. Industrial methods, such as steam-powered hydraulic hoses, made mining worthwhile in alluvia that otherwise would have been left untouched in the nineteenth century. These methods debuted in the gold strikes around the Pacific basin that began in the Californian Sierra in 1849 and shifted to Australia, New Zealand, and the Klondike. Hardrock mining, whether for South African gold and diamonds or Chilean copper, also required fossil-fuel powered machinery and transport. It inevitably pockmarked landscapes and occasion­ally, through surface collapses, altered topography. Late in the twentieth century, huge oil-powered machines chewed their way through mountains and valleys, extracting coal in West Virginia or gold in Western Australia. These environmental changes could not have happened without cheap energy: no amount of slaves with pickaxes could have done the work economically.

Furthermore, cheap energy created transportation networks that made intercontinental migrations on the part of tens of millions feasible. Between 1840 and 1913, some 60 million Europeans crossed oceans in search of better lives, and many of them ended up staffing the farms and mines of the Americas and Antipodes (and a few million more in Siberia). Another 20 or 40 million Indians and Chinese migrated to the world's economic peripheries, to the mines and plantations of Guyana, Trinidad, Mauritius, Malaya, Thailand, Burma, Natal, Queensland, and Fiji. Without these millions of strong backs and skilled hands, far less forest could have been cleared, far less slurry dumped, far less soil eroded, and far less prairie plowed.

Fossil fuels and industrialization worked their transformative magic not only in the world's far-flung plantation zones and mining camps, but also in and around industrial cities themselves. Early in the age of fossil fuels, the

Fig. 2.2 Coffee plantation in Brazil (© Bettmann/Corbis)

most conspicuous changes arose where industrial cities sprang up from former villages or small towns, as at Manchester, Berlin, or Chicago, and eventually at Shanghai, Osaka, Magnitogorsk, and many others. These were the “shock cities” of the industrial revolution, the places where water power or coal came together with uprooted peasantries and raw cotton or iron ore in a profitable mix.^[48] In parts of the carboniferous crescent, such as the Ruhr or Silesia, farmland sprouted iron mills, coal mines, metallurgical plants, and railroad yards almost overnight (Fig. 2.3).

These cityscapes and industrial belts became the most polluted and unhealthy habitats of the nineteenth century. Their rivers and canals hosted all manner of industrial chemicals and biological wastes. A British royal commission in 1866 found that the water of the Calder River made a “tolerably good ink.” Rivers and lakes acquired a frothy foam and often became toxic to almost all aquatic life. Some rivers and canals frequently caught fire. Meanwhile chimneys spewed out ash, dust, smoke, soot, and sulfur dioxide, blanketing homes, gardens, streets, pastures, and fields - and

Fig. 2.3 Soviet Russian propaganda poster from 1920s illustrating the growth of industry (World History Archive/Alamy)

filling lungs - with toxins. Tens of millions of lives were shortened by urban air pollution after 1800, maybe more than a hundred million. Veteran news­paper editors in Britain knew to leave extra space for obituaries when winds died down or fog settled on their city. Environmental battles took shape within and around the cities, as victims of these “nuisances” tried to stop, or win compensation for, the harm done them. For many decades they lost more than they won.

After 1950, urban air and water pollution got worse and then got better. With the arrival of the motor car as a routine middle-class possession (in the 1920s in the United States, 1950s in Western Europe), tailpipes joined with smokestacks and chimneys in fouling urban air. Photochemical smog made its debut as an ingredient in the toxic atmospheric stew. Where strong sunshine and millions of cars combined, as in Los Angeles in 1943, smog occasionally fooled residents into thinking they were under attack with chemical weapons. Meanwhile the rise of petrochemical industries added a new tang to the brew, and the rise of organic chemicals - often persistent in the environment for years or decades - further raised the risks to health and life in those landscapes within reach of industrial processes. Popular environmentalism, government regulation, and fuel substitution - more gas and less coal - combined after 1965 to clean up the air in most cities of Western Europe, Japan, and North America.

Soon, however, industrializing cities in China, India, Brazil, and else­where peppered their air with a slew of pollutants, mainly from the combustion of fossil fuels. Chinese high-sulfur coal powered the fastest industrial revolution in world history, but killed tens of millions of Chinese (and some Koreans and Japanese too) via lung ailments derived from, or exacerbated by, air pollution. After 2000, burgeoning fleets of private automobiles crawled across the pavements of Beijing, New Delhi, Sao Paulo, and dozens of other cities, adding vast flows of unhealthy pollutants to urban air and residents' lungs. In the early twenty-first century, a dozen or more Chinese and Indian cities ranked near the worst in the world in air quality, and were probably more dangerous places to breathe than Pittsburgh, Glasgow, or Essen a century before. It remains to be seen how long this deadly situation will last.

Fossil-fuel based industrialization had parallel unwholesome impacts on urban water. Metallurgical, chemical, and other factories typically used urban waterways for their waste streams, dumping all manner of toxins economically (for the factories) but lethally (for aquatic creatures). Bacterial pollution, however, was more dangerous for humans than all but the nastiest

Fig. 2.4 Aerial view of cattle pens in Chicago stockyards, 1950s (ClassicStock/Alamy)

chemicals. Industrial transport made it possible to bring enough food and fuel into cities after 1820 so that some could grow into megalopoli. London grew from i million to 7 million in the nineteenth century. Chicago grew from nothing into a city of half a million in 1880, i million by 1890, and 2 million by i9i0. Meanwhile, between i890 and i920 its coal consumption sextupled. It built the world's largest stockyards and slaughterhouse complex, and butch­ered 13 million animals a year (Fig. 2.4). Packing humans and animals in together on such a scale created flows of faeces and offal of prodigious magnitude, fouling cities' streets and especially their waters. Cholera, typhoid, and other waterborne diseases ricocheted around these cities, killing millions. Happily, in the early twentieth century, filtration and other forms of pollution control drastically reduced the lethality of urban water. Such measures proved comparatively cheap and easy to install, and in rich coun­tries were nearly universal by 1940. They spread to hundreds of colonial cities, although sometimes only to the “European quarters,” in the mid­twentieth century. In the post-colonial world, they are still spreading, but many of the fast-growing cities in the poorest countries, Dhaka or Port-au- Prince, for example, cannot provide clean water for their residents. It also remains to be seen how long this deadly situation will last.

Population and urbanization

The Anthropocene witnessed unprecedented global population growth. Indeed, that is one of its defining characteristics: to some appreciable (but not measurable) extent, population growth led to the Anthropocene. One way to recognize the extraordinary character of the Anthropocene is to consider rates of population growth.

For most of human history, population growth rates were infinitesimal (Table 2.3; Map 2.1). In the nineteenth century, growth attained a rate of about 0.5 percent per annum and in the first half of the twentieth, about 0.9 percent. A great spike followed the Second World War: growth reached its apex about 1970, briefly topping 2 percent per year. By 1975, the rate of growth started to slacken, then fell fast after 1990, so that by 2010 it came to ι.ι percent per year. What the future holds is anyone's guess, but UN demographers project the growth rate by 2050 will dip to 0.34 percent, slower than in 1800. In any case, the era from 1950 to 1990, when global growth exceeded 1.75 percent per year, amounted to a global burst of reproduction and survival, never before approached and never to be repeated in the history of our species. These modern growth rates are 50 to 200 times as fast as those that prevailed for most of our species's history. Between 1945 and 2015, some two-thirds of the population growth in the history of our species took place - within one

Table 2.3 Annual rates of global population growth since ad 1000

Period

Percentage population growth

Sources: Rounded from Angus Maddison, The World Economy: Historical

Statistics (Paris: OECD, 2003), p. 257; UN Population Division data

Table 2.4 Global population since ad 1000 (millions)

Source: Angus Maddison, The World Economy: Historical Statistics (Paris:

OECD, 2003), p. 256; RIVM HYDE database; US Census Bureau

human lifetime (Map 2.2). If our descendants keep such rates up for another few centuries, the Earth will be encased inside a giant ball of human flesh expanding outwards at a radial velocity approaching the speed of light - an unlikely prospect.

A second way to consider the extraordinary population history of the Anthropocene is to focus on sheer size. It took our species many tens of thousands of years, including a brush or two with extinction, to become i billion strong. That came between 1800 and 1820. By 1930, human popula­tion had doubled to 2 billion. It took only another thirty years, until i960, to add the third billion. Then the crescendo came. The fourth billion arrived in 1975, joined by another by 1987 and then another by 1999. By 2011 or 2012 the world counted 7 billion people, and had been adding a billion every twelve to fifteen years for two human generations (Table 2.4).

Human numbers more than doubled between 1950 and 2000. In no prior period of fifty years, in no other prior century, did human numbers ever double. No other primate, probably no other mammal, has ever done any­thing like this in the history of life on Earth.

One last way to look at this extraordinary burst of population growth is to consider the absolute increase in the number of people per year, the annual increment or the net of births minus deaths. From 1920 to 1945, the globe had added on average a little over 20 million people every year. By 1950, the annual increment approached 50 million, after which it surged to about 75 million by the early 1970s, stabilized briefly, then in the late 1980s reached what is likely to be its maximum at about 89 million per year - equivalent to

Table 2.5 Global population increment per year, 1950-2010

Source: Rounded from UN Population Division data

adding a new Germany or Vietnam (at their 2010 populations) every twelve months (Table 2.5).

Our recent biological success is remarkable in biospheric context. As of 2015, we outnumbered any other large mammal on Earth by a large margin. Indeed our total biomass (about 100 million tons) outweighed any mammalian rival except cattle, of which there were about 1.3 billion, weighing in at 156 million tons. Humans (whose average body size increased by half between 1800 and 2000), now account for perhaps 5 percent of terrestrial animal biomass, half as much as all domestic animals combined. Lest we grow smug at our biological success, we should remember that ants, however, easily outweigh us.⁷

Why did this bizarre episode in our demographic history happen? On the most basic level, it happened because the global death rate fell rapidly, from about thirty to thirty-five per thousand per year in 1800 to about 20/1000 in 1945, before plummeting to 10/1000 by the early 1980s. It now stands at 8.4/1000. The birth rate fell too, but more gradually, and in some places actually rose for a few decades before beginning its secular decline. Globally the crude birth rate slid from 37/1000 in 1950 to 20/1000 in 2010, a notable fall, but less so than the precipitous decline in the death rate.

On a less elementary level, what happened was that techniques of death control temporarily outstripped techniques of birth control. In the

7 Estimated from FAO (Food and Agriculture Organization of the United Nations) 2014.

Statistical database, http://faostat.fao.org/site/573/default.aspx#ancor.

course of the eighteenth century in some parts of the world, notably China and Western Europe, improved government response to food shortage, combined with gradual build-up of disease resistance slowed death rates. In the nineteenth century, these processes continued and were joined by revolutionary changes in urban sanitation, mainly the provision of clean drinking water beginning around 1880, and in the early twentieth century by vaccinations and antibiotics as well. States (eventually including colonial administrations) created public health agencies that sought to impose vaccination and sanitation regimes wherever they could. Medical research also identified several disease vectors, lice, ticks, and mosquitoes for instance, and in some cases proceeded to find ways to keep vectors and people apart. Successful mosquito control sharply curtailed the ravages of yellow fever and malaria, for example. Moreover, food scientists in the 1920s and 1930s figured out the role of specific vitamins and minerals in checking diseases caused by malnutrition. In the 1970s, a sustained interna­tional effort eradicated smallpox, humankind's deadliest nemesis for several millennia. Curtailing infectious disease proved the most important inter­vention in the fruitful quest to limit death and lengthen life. Famine reduction came a distant second.

After 1945 most of these developments came together to lower death tolls very quickly in most parts of the world. Hence a tremendous surge in life expectancy, derived mainly from the survival of billions of children who in earlier times would have died very young. In the second half of the twentieth century, even poor people lived far longer (on average about twenty years longer) than their forebears had a century previously. The gaps between rich and poor in life expectancy narrowed almost to nothing, probably for the first time since plant and animal domestication.

This rollback of death was a signal achievement of the human species and one of the greatest social changes of modern times. But the end of the twentieth century brought two exceptions that proved the rule. First, in Russia, Ukraine, and some of their smaller neighbors, life expectancy (which in the Soviet Union had lengthened rapidly between 1946 and 1965) declined after 1975, at least for males. This departure from the prevailing trend is usually attributed mainly to alcoholism and smoking. Second, after 1990 in the most AIDS-afflicted parts of Africa, a parallel reverse of lengthening life expectancy occurred - by as much as ten to fifteen years on average in Zimbabwe, South Africa, Botswana, and Kenya.

Since 1750, our species has changed its characteristic habitat from village to city. The first cities appeared 6,000-7,000 years ago. Not until eighth-century Baghdad did any city reach a million, and that did not last. By 1750, Beijing alone topped ι million and less than 3 percent of humankind lived in cities. There were good reasons for this: supplying a concentrated population with enough food and fuel was a difficult technical and economic problem. Cities in temperate latitudes (northern Europe or China) needed forest areas 50 to 200 times their size to meet their fuelwood needs. London, which burned coal on a substantial scale as early as the sixteenth century, was the lone exception. These requirements put a fairly firm limit on urbanization. So did stubborn constraints upon agricultural productivity.

After 1800, however, the development of fossil fuels reduced the require­ments for fuelwood and, with technical improvements in engines and transport, allowed cities to extend their footprint, or catchment, over greater distances. By 1900 about 14 percent of people lived in cities, and by 2000 very close to 50 percent. Thus the proportion of urban-dwellers among our species quadrupled in the nineteenth century and then tripled in the twentieth. In raw numbers, the urban population in 1800 was about 30 million, in 1900 some 225 million, and in 2000 perhaps 3 billion. This comes to a 100-fold expansion in 200 years, roughly the same as the expansion in energy use. Nothing like this ever happened before in human history, nor can it again.

Until a century ago, cities were lethal environments. Their infectious diseases killed people faster than others were born. Around 1750, for example, London's pathogens canceled out half of the population increase of the rest of England. In 1796, a German physician referred to large cities as the “open graves of mankind.”^[49] But between 1850 and 1930 sanitation improvements revolutionized urban demography, so that after 5,500 years as black holes for humanity, cities by the early twentieth century ceased to prune back population growth. Villages continued to send their legions of young migrants to the world's cities, but now more of them survived and reproduced; hence the emergence of megalopoli and the swift urbanization of our species.

For 200,000 years, our characteristic environment was savanna grasslands and parklands. For 7,000 years until 2000 ce, farming villages formed the standard human habitat, but now cities do. Cities account for only a sliver of the Earth's surface (less than 1 percent), but they are now the environment most people experience for most of their lives.

Politics: imperialism and international tensions

Energy and industrialization, population growth and urbanization brought on the Anthropocene. But other forces helped shape its character, such as politics. In 1750, most polities were monarchies run by narrow cliques of usually aristocratic men (and occasionally women). From the early nine­teenth century, however, more and more governments had to acknowledge the preferences of larger and larger shares of the populations they ruled. This was democratization, slow and spotty in the nineteenth century, in retreat for part of the twentieth, but advancing broadly if inconsistently after i960 or so, what with decolonization in the Caribbean, Africa, and Asia, quiet revolu­tions in parts of Southeast Asia, and the fall of the Soviet empire. Broadly speaking, the enfranchisement of some of the masses gave rise to higher rates of consumption, more industrialization, and more environmental disruption. After several decades, however, it often brought a countervailing trend, in the form of agitation for healthier air and water, and occasionally for the preservation of certain ecosystems. (The surge of modern environmentalism around the world is treated below.)

At the same time as many states and societies became more democratic, the international system became more hierarchical. In the eighteenth century a few states, such as Qing China, Russia, and Britain, managed to expand their domains in Central and South Asia through military might and forceful diplomacy. In the nineteenth century, Western European states (and later Japan and the United States too) rapidly built sprawling empires in Africa, Southeast Asia, or the Pacific. It was their industrial power more than any­thing else that permitted them to do so.

Imperialism, like every major political process, had its environmental impacts. In the first place, imperialism eased the extraction of the raw materials (from the mines and plantations discussed above) that industrial economies needed. Empire builders also encouraged the migration of people, plants, and animals from one corner of the globe to another, such as millions of Britons to Australia, French to Algeria, or South Asians to South Africa, Trinidad, Fiji, and elsewhere - as well as eucalyptus trees from Australia to Portugal and camels from Afghanistan to Australia. Of course people had been reshuffling the planet's biota for millennia. But now, thanks to imperi­alism and cheaper, faster transport, the pace quickened. Put differently, imperialism favored the ongoing process of ecological globalization.

Empires also provided convenient landscapes for experiments in environ­mental management. In the quest for economic development, disease control, or some other worthy goal, imperial bureaucrats and engineers instructed colonized peoples to dig irrigation channels, drain swamps, build dams, terrace fields, fence pastures, cull herds, or otherwise improve their environments. Frequently they translated expertise from one part of the world to another, from home to the colonies, or from one colony to another, just as they did with plants and animals. As with biotic transfers, the transfer of expertise sometimes worked as intended, and sometimes brought a cascade of unexpected and unwelcome consequences, such as extra doses of malaria and bilharzia around irrigation projects.

International politics, as always, included war as well as imperialism. Combat itself often included programs of environmental disruption in the form of scorched-earth tactics, poisoned wells, and so forth, all of it as old as warfare itself. Preparing and mobilizing for war also had its ecological dimensions. Before 1870, that often included measures to try to protect forests of pine and oak woodlands, so as to keep ample supplies of naval timber (after 1870 warships increasingly were made of metal rather than wood). Before 1920, it also often involved maintaining landscapes suitable for horse-raising to keep armies flush with cavalry mounts and dray horses to haul field artillery. War preparation also entailed building roads and railroads which when not in military use could ease agricultural expansions, timber cutting, or extend mining frontiers. The Trans-Siberian railway, begun in 1891 and built primarily for military reasons, did all of the above.

After 1890, the great powers increasingly felt the need to build enduring military-industrial complexes. Small ones had existed before in wartime, but in peacetime were usually dismantled. But after 1890, what with sustained great-power rivalry, two world wars, and then the Cold War, major economies such as Germany, Russia, Britain, and the United States maintained large-scale military-industrial complexes for decades on end. Governments shielded these from environmental regulation (when and where it existed), so military industries became giant polluters and usually stayed that way. As warfare became more mobile in the mid-twentieth century, militaries became voracious consumers of fuel. Advanced fighter jets used more oil in an afternoon than an average American family used in a year.

After 1945, several of the great powers added nuclear weaponry to their arsenals. In the second half of the twentieth century, roughly 10 percent of all electricity consumption went into the manufacture of nuclear weapons. Building them and testing them led to ongoing radiation contamination, occasionally to the point where authorities had to seal off exclusion zones in the interest of human health. One hour spent beside Lake Karachai, in the heart of the old Soviet nuclear weapon-making region, is enough to kill anyone by radiation poisoning. If the Anthropocene requires a “golden spike,” the layer of radionuclides from atomic weapon-testing will do for now: it should remain detectable by geologists for at least 100,000 more years.

Climate change

In the fullness of time it may appear that of all the environmental changes that formed the Anthropocene, the most important was in climate. But that is not true yet.

In 1750, the Earth's climate, always in flux, was in the latter stages of the Little Ice Age (c. 1300-1800), a period of slightly cooler temperatures in most parts of the world and more frequent drought in many. The exit from the Little Ice Age at first was probably an entirely natural phenomenon. By 1850 or so, however, the twin processes of burning fossil fuels and clearing forests had begun to inject enough carbon into the atmosphere to begin a long-term trend of human-caused climate change. Its chief characteristic was warming of the lower atmosphere, by about ι degree Celsius on average (1850-2015). Most of that took place after 1975. It was more pronounced in the Arctic than anywhere else, but evident almost everywhere (despite the occasional cold winter here and there). Barring some powerful override, such as reduced solar output, the trend is set to continue for the foreseeable future - which is why, in time, it is likely to appear the most important environmental disruption in an age of several such disruptions.

The warming led to glacial melt almost everywhere, and a dramatic shrinking of the north polar ice cap. Melting ice, combined with thermal expansion, raised sea level by about 30 cm (on average, 1850-2015). Higher sea levels made coastal communities more vulnerable to storm surges - such as the one that hammered New Jersey in 2012, and the many that flood low-lying landscapes in the Philippines or Bangladesh almost every year. Less dramatically, rising seas allowed salty water to seep into aquifers, endanger­ing drinking water from Cape Cod to Catalonia to Calabar to Calcutta.

Climate change pushed plants and animals sensitive to temperature into new habitats, and pushed a few species, unable to make such migrations, into extinction. Warmer temperatures probably raised the frequency of extreme weather, both droughts and floods, by accelerating evaporation and loading the atmosphere with additional water vapor. Greater warmth expanded the range of some disease vectors, such as anopheline mosquitoes, which have crept up the slopes in Ethiopia's highlands, for example, bringing malaria to populations formerly free of it. It permitted population explosions of bark beetles in boreal forests, such as those nibbling their way through British Columbia's valuable timberlands. More cheerfully, climate change length­ened growing seasons in most parts of the world, allowing vineyards to thrive in southern Britain for the first time since the reign of Richard the Lionheart. The history of anthropogenic climate change is still in its early days, and may look rather different in just a few decades.

The recognition of climate change, and anxieties about future prospects, animated a new dimension of international politics - climate politics - which centered on the question of how to reduce carbon (and other green­house gas) emissions to the atmosphere. In practice, it became a politics of near total futility, featuring prodigious grandstanding and hypocrisy, centered on how to make other people reduce emissions without doing much oneself.

Ecological changes

While in the fullness of time, climate change may become the hallmark of the Anthropocene and its most important legacy, in the interim other ecological consequences of the surges in energy use, economic activity, population, urbanization, technological change (and so forth) loomed larger. One such consequence was reorganization of the terrestrial biosphere, mainly moti­vated by the quest for food. In 1750 about 4 percent of the world's land area was in crops or pasture. By 2015, the figure had climbed to 40 percent. In the same span, world food production climbed about eighteen-fold.

Most of that cropland came via a giant plow-up of the world's grass­lands. Between 1750 and 1950, about 18 million km² (an area equivalent to today's Russia) of grasslands were converted to other uses, mainly cultivation. Another 9 million km² (equivalent to China) followed after 1950. The prairies of North America, the Argentine pampas, the Russian and Ukrainian steppe, big chunks of northern China, southeastern Australia, the West African Sahel, and much grassland elsewhere, was turned to cropland, sometimes permanently, sometimes only briefly. The last big push in this global frontier process came in 1955-1963 with the Soviet Virgin Lands scheme, in which wheat replaced steppe grasses over an area the size of Japan (or Montana). The process from the outset was intimately linked with the trends in fossil fuels and demography: growing populations required the grain that these former grasslands gave; railroads and steamships allowed the grain to reach markets cheaply enough to allow even poor people to eat it; and, beginning in 1920 or so, oil-powered farm machinery (e.g. tractors) made it much more economical to plow up the densely rooted grasses and to harvest grains.

The Anthropocene was - and is - an age of swamp-busting as well as grassland conversion. In China, the lower Ganges, the Po marshlands, the North and Baltic Sea littorals, and elsewhere, the engineering expertise needed to drain wetlands and turn them to farmland had existed for centuries before 1750. That expertise spread round the world in the nineteenth century, with imperialism, settler colonies, and an international fraternity of hydraulic engineers. The necessary manpower became easier to find, and eventually fossil-fuel powered machinery made it easy work. Broad swathes of North America, including the Middle West breadbasket, were drained after 1850. Eventually between a quarter and a half of the world's wetlands (as of 1750) disappeared. In warm or seasonally warm climates this often reduced the burden of malaria, and almost everywhere it yielded lush farmland, but was hard on people who had depended on fish and waterfowl for their food. The losers were often ethnic or religious minorities, without the wherewithal to challenge states bent on draining wetlands, settling farmers, raising revenues, and, as they often saw it, extending civilization. Various governments in Iraq, for example, from Ottoman times onward, tried to drain marshes amidst the Tigris and Euphrates where people lived outside the state's net of taxation and conscription. Saddam Hussein completed the process, destroying the habitat of the so-called Marsh Arabs in Basra province. After 1970 in a few corners of the world, notably the United States, environmentalism made swamp-busting unpopular and governments withdrew support, even trying to rehydrate drained wetlands such as (parts of) the Florida Everglades. In net global terms, however, wetlands continue to shrink.

With gathering speed, people turned forests, as well as grasslands and wet­lands, into farms. Deforestation was another hallmark of the Anthropocene, driven by hunger for farmland and markets for timber. People have cut and burned forests for as long as there have been people, and where they did it regularly or replaced forest with fields or pastures, their impact endured as deforestation. In the eighteenth and nineteenth centuries, the main frontiers of deforestation were the temperate lands of Eurasia and North America. By the mid-twentieth century, however, the fastest forest retreats took place in the moist tropical forests of Latin America, Africa, and Southeast Asia. In North America and Europe, meanwhile, forests slowly returned. In the United States,

Fig. 2.5 A Mexican official walks amid deforestation in Lacandon rainforest, Montes Azules (© Reuters/Corbis)

for example, the nadir of forest cover came in about 1910, since which time trees have recolonized large sweeps of the eastern part of the country. The North American and European forest recovery was matched or exceeded in Japan, but in global terms remains for now an eccentricity. The surge of cutting and burning after 1950 has reduced the global extent of moist tropical forest by about 60 percent. Lately the pace has dwindled, especially in Brazil. That might be a blip or it might be a new trend (Fig. 2.5).^[50]

The transformation of grasslands, wetlands, and forests took a toll on wildlife. Since the acquisition of fire, people have been dangerous to other animals. Hunting probably helped drive dozens of large mammals to extinction at the end of the Pleistocene. Subsequently, human settlement, especially on formerly isolated islands, and subsequent habitat conversion combined with hunting drove a few more species to extinction. But the pace of animal and plant extinction accelerated markedly in the nineteenth and twentieth centuries, and still gathers pace. The main reason for that is the scale of habitat loss for species other than humans and their preferred domesticates. As people burned off tropical forests at unprecedented rates after i960, they disrupted zones of high biological diversity. A typical patch of intact Amazonian forest might have 100 to 1,000 times as many species as a same-sized patch of forest in Ontario. So the geographical location of defor­estation carried vast implications for its impact on biological diversity. Late in the twentieth century, biologists concluded that the scope and speed of species loss had reached the point where life on Earth had entered into its sixth great spasm of extinctions, the first in 65 million years.^{[51] [52]}

The sixth extinction dipped into the seas as well. Here habitat loss played a smaller role until late in the twentieth century, and the marine versions of hunting - fishing and whaling - loomed larger than on land. Fishing pressure had affected fish populations and marine ecosystems before 1750 in select spots. But the advent of steam-powered trawlers and refrigerated railway cars for shipping fish to inland markets changed the seascape forever. By the 1890s the North Sea and the Gulf of Maine showed signs of overfishing. In the next decades the most energetic expansion in fisheries took place in the waters around Japan, which built the world's largest trawler fleet and by 1930 became the world's number one fishing nation. Soon marketable fish in accessible waters grew scarce, and the Japanese fleet had to roam further from home, creating conflicts with China. After the Second World War (a respite for the world's fish), a general planetary assault on edible fish began. New technology made fishers ever more efficient but no more likely to preserve their resource. One after another the great fisheries of the world were overfished, fewer and smaller fish were landed, and some of the historically most abundant, like the North Atlantic cod fishery, crashed (in the early 1990s) and have yet to recover.¹¹

Whaling initially exhibited much the same pattern. While people had chased whales for centuries - medieval Arabic texts mention whaling in the Indian Ocean - the scale of operations ratcheted up in the 1780s as demand for whale oil for illumination and lubrication mounted (not least in factories running round the clock). By 1860 the most suitable whale species, the sperm and right whales, were on the cusp of extinction (Fig. 2.6). By 1890, so was the Arctic bowhead. Whalers soon shifted their attention to the Southern Ocean,

Fig. 2.6 Whalers of the South Seas Fishery by John Ward of Hull (Christie's Images/Corbis)

home to the biggest animals on Earth, blue whales. Too big and fast to catch by traditional means, these whales prospered unmolested until new technol­ogies put them at risk in the early twentieth century. By the 1930s, blue whales were scarce too. Whaling paused during the Second World War but roared back in the 1950s and 1960s, led by Japan and the USSR, to the point where almost every whale species was in danger of extinction. Having nearly killed the goose that laid their golden eggs, the world's whalers - unlike fishers - devised and accepted global regulation. The International Whaling Commission, formed in 1946, at first served as the fox guarding the henhouse. But by 1982 it had acquired more backbone, and imposed a moratorium on whaling in which all but Japan, Norway, and Iceland acquiesced. Since the moratorium, the world's whale populations - as far as one can tell - have begun to recover.

In addition to the sharp reductions in fish and marine mammals, the Anthropocene at sea appeared in the guise of marine pollution on a new scale. Thanks to the invention of durable plastics, the world's oceans became home to gigantic twirling middens of trash in the late twentieth century. The largest of these, in the Pacific between Hawai'i and California, is about twice the size of Texas, a slow-moving gyre of sodden plastic confetti spiced with the occasional kayak, dinghy, or rubber duck. It is continually fed by plastic swept out to sea by the rivers of the Pacific Rim, and by the contents of transpacific shipping lost overboard in high seas. Most plastics can last decades, and some probably for centuries, before they fully degrade, so it takes only a tiny proportion of the production of the world's petrochemical plants to keep the plastic gyre afloat. Increasingly, the fish, sea birds, and marine mammals of the world, especially those of the northern Pacific, ingest plastic with their meals. Those creatures resistant to the variable (usually mild) toxicities of plastic should prosper: natural selection in this case, as in many other environments, has acquired a new twist.

For all species, on land and sea, the Anthropocene has revised the rules of evolution. Biological fitness - defined as success in the business of survival and reproduction - has increasingly hinged on compatibility with human enterprise. Those species that fit neatly into a humanized planet, such as pigeons, squirrels, rats, cattle, goats, crabgrass, rice, and maize prosper. Others, especially ecological specialists dependent upon specific environ­ments, such as pandas upon bamboo forests, go to the wall.

Environmentalisms

The progressive endangerment of charismatic megafauna - whales, rhinos, elephants - combined with intense pollution and its attendant human health risks helped to crystallize the modern environmental movement. A cultural and political phenomenon that has begun to affect ecology in modest ways, environmentalism has a tangled and deep root structure, involving British and French imperial administrators, American diplomats, Brazilian slave-owners, German forest managers, Himalayan peasants, Chinese literati, ancient philosophers and kings - and many others of whom historians have yet to find evidence. Their concerns ranged from soil erosion and wildlife extermination to shortages of naval timber and unruly floodwaters. State efforts to restrict deforestation go back at least 600 years, and anti-pollution laws at least 700. It was normally difficult to enforce such rules as existed even when emperors or legislatures fervently wished to protect environments. The power of the state to regulate the conduct of its subjects or citizens with respect to the environment was sorely limited in pre-modern times, but the rise in the last two centuries of more effective regulatory states allowed a more consequential regulatory environmentalism.

Pre-modern efforts to address environmental ills were normally specific in their targets. They identified “nuisances,” a particular source of pollution, and sought to regulate it. These were local in scope, involving a single tannery or glassworks, or at most the tanneries of a particular city. An exception was the widespread state concern over naval timber supplies, which sought to preserve trees from quotidian exploitation so that in time states might cut them. Another was the hunting grounds of princes, particu­larly in India, protected from peasant use so that royalty might enjoy a sport of kings.

Less self-interested nature preservation, more conventionally connected to the concept of environmentalism, arrived in the late nineteenth century, driven by disillusionment with urbanization. From the 1870s onward several countries created nature preserves and national parks. This was an elite environmentalism, advanced by politically connected men (and some women), concerned that economic progress might destroy majestic land­scapes. The United States, Canada, Australia, and South Africa, among others, began to establish national parks in their most scenic areas, an undertaking that often involved expelling indigenous peoples, ranchers, or hunters. After the revolution of 1917, the USSR expanded an archipelago of nature preserves intended for scientific research, not scenic enjoyment. This wave of environmental concern washed over only parts of the world.

A second wave, which gathered in the 1960s, proved more global. Modern popular environmentalism has multiple variants and countless parents, but nothing did more to make it politically prominent than the urban air and water pollution of the mid-twentieth century, which galvanized effective coalitions into forming. Urban populations normally made their voices heard in the corridors of power more effectively than could scattered peasantries; the issues surrounding urban pollution were on the one hand easily tangible, visible, and smellable, and on the other demonstrably threatening to human health. Moreover, the threats were not easily confined to the politically disenfranchised urban slum dwellers. Dangerous air and water sometimes menaced the rich and powerful in the cities too.

For all these reasons, between i960 and 1980 a new environmentalism washed over the world, from the cities ofJapan, Europe, and North America to the forests and floodplains of India and Brazil. It flourished in open societies suffering from conspicuous environmental problems, such as Sweden, where acid rain damaged lakes and industrial and urban effluent threatened the Baltic Sea. It served as one of the few tolerated forms of public dissent in parts of the old Soviet bloc, such as Hungary and Poland, and does so today in China. It became a routine feature of politics in some places, such as the Netherlands, Germany, and Canada, and an ideology of

insurgency in others, such as Peru. It has become a capacious and incoherent global movement, loosely uniting peasants concerned with access to forest resources, urbanites worried about air quality, and everyone vexed by climate change or overfishing. It has been adopted as a priority, rarely a high one, by hundreds if not thousands of government bodies and corporations, and forms part of the education of almost every schoolchild around the world. To date, however, states and societies retain their traditional priorities of military secur­ity and economic growth, tempered only somewhat by environmentalism.

Environmentalism gathered momentum when it did because the ecologi­cal disruption of the modern world had reached an unprecedented scale and pace, and because a ready audience emerged. The environmental turbulence of the years 1800-1950, when coal was king and industrial demand and long­distance migration remade the world's frontiers, was unsettling to hundreds of millions. But most of them had no way of uniting with others as aggrieved as themselves, no way to coalesce as a political and cultural movement. After 1950, with pell-mell urbanization, ever-cheaper transport and communica­tion, not to mention higher literacy and (on balance) less censorship and political oppression, an audience for environmentalism formed just as the oil age added new environmental concerns on top of the old. The post-1950 environmental tumult, with its local and regional anxieties about accelerated deforestation, overfishing, soil erosion, and urban pollution, and eventually its global concerns about population growth, climate change, and the ozone hole, had something to worry almost everyone.

Conclusion

Whosoever is writing a modern History, shall follow truth too neare the heeles, it may haply strike out his teeth.

- Walter Ralegh, 1614

Sir Walter Ralegh recognized the hazards of trying to distill meaning from a story still in full gallop. The environmental history of the world since 1750 has been tumultuous, and that tumult is still in train. It is too soon to tell just about anything, roughly analogous to assessing the history of the Second World War in early 1943. It may be that in fifty or seventy years the main drivers of rapid environmental changes - fossil fuel energy use and popula­tion growth - will have dwindled, and the gallop slowed to a stately walk. If so, that will be a good time to look back and assess modern environmental history. Until then, premature assessments like this one will have to do.

A group of Austrian scholars, using an abstract, generalized index of human impact on the environment, estimated recently that that impact doubled in the eighteenth century, and doubled again in the nineteenth. It doubled again, 1900-1950, and then tripled in the latter half of the twentieth century. Cumulatively, this comes to a twenty-four-fold increase in human environmental impact 1700-2000, and the figure would be about the same for the years 1750-2015. This is no more than a heuristic device, but it helps as a simple way to think about the planetary consequences of human actions in the modern period. One might revise the coefficients up or down a bit (I would lower it for the eighteenth century and raise it for the post-1950 period), but the general impression this exercise conveys - tumult - is the right one.^[53]

The last 250 years amount to the most tempestuous period in the relationship between humankind and the natural world since the eruption of Mount Toba some 73,000 years ago. That event brought a prolonged “volcanic winter,” pushing our ancestors to the brink of extinction. Climate change has battered humankind time and again, and people have altered (and occasionally obliterated) this or that bit of the biosphere over the millennia. Big changes have occurred, such as domestication, or the Columbian Exchange. But there has been nothing like the scale and scope of environmental change since 1750.

Thus it is apt to refer to this period, whether starting in 1750 as this chapter does, or 1800 or 1850 - for which good arguments could be made - as the Anthropocene. And it is within this rapidly evolving bio-geophysical context, the Earth and all its systems, that what historians habitually call modern history played itself out. Humans changed the environment, and the changing environment changed humans. That embrace is as it always has been, except lately it acquired an ever greater intensity and speed, like a spinning figure skater in an ever tighter spiral.

Further reading

Blackbourn, David. The Conquest of Nature: Water, Landscape, and the Making of Modern Germany. New York: Norton, 2006.

Cronon, William. Nature's Metropolis: Chicago and the Great West. New York: Norton, 1991.

Crosby, Alfred. Children of the Sun: A History of Humanity’s Unappeasable Appetitefor Energy. Cambridge University Press, 2007.

EcologicalImperialism: The Biological Expansion of Europe, 900-1900. Cambridge University Press, 1986.

Cushman, Gregory. Guano and the Opening of the Pacific World: A Global Ecological History. Cambridge University Press, 2014.

Guha, Ramachandra. Environmentalism: A Global History. New York: Longman, 2000.

Habib, Irfan. Man and Environment: The Ecological History of India. Aligarh Historians Society, 2011.

Josephson, Paul, et al. An Environmental History of Russia. Cambridge University Press, 2013. Kolbert, Elizabeth. The Sixth Extinction: An Unnatural History. New York: Henry Holt, 2014. Kumar, Deepak, Vinita Damodaran, and Rohan D'Souza, eds. The British Empire and the Natural World: Environmental Encounters in South Asia. Oxford University Press, 2011.

McNeill, J. R. Something New under the Sun: An Environmental History of the Twentieth Century. New York: Norton, 2000.

McNeill, J. R., and Erin S. Mauldin, eds. A Companion to Global Environmental History. Oxford: Wiley-Blackwell, 2012.

Meinert, Carmen, ed. Nature, Environment and Culture in East Asia: The Challenge of Climate Change. Leiden: Brill, 2013.

Miller, Shawn. An Environmental History of Latin America. Cambridge University Press, 2007.

Muscolino, Micah. Fishing Wars and Environmental Change in Late Imperial and Modern China. Cambridge, ma: Harvard East Asian Monographs, 2010.

Platt, Harold. Shock Cities: The Environmental Transformation and Reform of Manchester and Chicago. University of Chicago Press, 2005.

Pomeranz, Kenneth. The Great Divergence: China, Europe, and the Making of the Modern World Economy. Princeton University Press, 2000.

Radkau, Joachim. The Age of Ecology. NewYork: Wiley, 2014.

Nature and Power: A Global History of the Environment. Cambridge University Press, 2008. Richards, John F. The Unending Frontier: An Environmental History of the Early Modern World. Berkeley, ca: University of California Press, 2003.

Ross, Corey. Nature and the New Imperialism: Europe and the Ecological Transformation of the Tropical World, 1870-1960. Oxford University Press, forthcoming.

Santiago, Myrna. The Ecology of Oil: Environment, Labor, and the Mexican Revolution, 1900-1938. Cambridge University Press, 2009.

Smil, Vaclav. Energy in World History. Boulder, co: Westview Press, 1994.

Harvesting the Biosphere: What We Have Takenfrom Nature. Cambridge, ma: MIT Press, 2013.

Steffen, Will, J. Grinevald, P. Crutzen, and J. McNeill. “The Anthropocene: conceptual and historical perspectives.” Philosophical Transactions of the Royal Society A 369 (2012), 842-867.

Steinberg, Ted. Down to Earth: Nature’s Role in American History. Oxford University Press, 2002.

Tucker, Richard P. Insatiable Appetite: The United States and the Ecological Degradation of the Tropical World. Berkeley, ca: University of California Press, 2000.

Walker, Brett. Toxic Archipelago: A History of Industrial Disease in Japan. Seattle, wa: University of Washington Press, 2009.

Williams, Michael. Deforesting the Earth: From Prehistory to Global Crisis. University of Chicago Press, 2002.

Wohl, Ellen. A World of Rivers: Environmental Change on Ten of the World's Great Rivers. University of Chicago Press, 2011.

Zelko, Frank. Make It a Green Peace! The Rise of Countercultural Environmentalism. Oxford University Press, 2013.

Useful websites for quantitative data on energy, population, and environment include:

BP Statistical Review of World Energy at: www.bp.com/content/dam/bp/pdf/Energy- economics/ statistical-review-2014 /BP-statistical-review-of-world-energy-2014-full-report. pdf.

UN Population Division: www.un.org/en/development/desa/population/.

HYDE (History Database of the Global Environment) maintained by the Netherlands Environmental Assessment Agency: themasites.pbl.nl/tridion/en/themasites/hyde/.